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SummaryAs is known,one of the main barriers to a wider adoption of OLED technology resides in its lack of efficiency compared to fluorescent lamps or Light-emitting diodes(LED).  The SOLED project hoped to solve this problem using chiral organic semiconductor structures. The difference is undisputable: when put side by side with an LED display (display modules), its OLED counterpart will stand out thanks to its sharper images, better contrast and crisp colours.  BodyEnergy efficiency, however, is a key concern for consumers, and OLED is still lagging behind other technologies in this regard. In fact, the only type of display it can top is LCD, but only marginally.To solve this problem, the Weizmann Institute kicked off the SOLED (Chiral organic semiconductor structures) project in January 2016. They aimed to tackle the OLED efficiency problem at its source: ‘The low efficiency of OLED technology is a result of low light emission yield due to the formation of triplet electronic states, in which the two electrons have the same orientation,’ explains Prof. Ron Naaman, coordinator of SOLED.The project’s plan was to use electrons’ spin control with a view to reducing the probability of producing triplet states. This is known as the spin-LED/OLED concept: electrons injected into and from the light-emitting species have a predetermined spin, which helps avoid the formation of ‘dark’, non-emitting triplet states. The team had already benefitted from past experience in this field. They could capitalise on their earlier research on the Chiral-induced spin selectivity (CISS) effect, and proposed to develop chiral organic semiconductor structures to control the spin state of injected electrons and holes in OLEDs.As they initiated the SOLED project, they expected this effect to be able to increase the energy efficiency of OLED devices by a factor of four. Prof. Naaman said "The chiral-induced spin selectivity effect is supposed to allow full control of the electrons’ spin orientation by ensuring that the electron that leaves the emitting molecule has the same spin orientation as the electron entering into the molecule." "Whilst the concept was successfully demonstrated in principle, the team quickly realised that further research would be required to reach their objective. In collaboration with the group of Richard Friend from Cambridge and E. W. (Bert) Meijer from Eindhoven, we could demonstrate our ability to affect the spin orientation in the OLED, but the efficiency of the process was not very high." . "The reason for it is the organisation of the molecules in the OLED. Now, we pursue this work with our collaborators towards better control of material organisation." Until this problem is solved, the team has had to postpone the pre-commercialisation measures they had originally planned for. However, Prof. Naaman is still hopeful that the technology will help OLED technology spread throughout European homes in the form of flexible light emitters. He also underlines the realisation that material organisation is the key factor in achieving spin control as a major outcome for the project. At the end,Prof. Naaman concluded:"We intend to study molecules that self-assemble into three dimensional organised structures, like micro-crystals. We hope to do that under either the FET-OPEN programme or other specific programmes." 

A few months ago,I have see an article about desinging a nixie tube clock with an ATmega328 and ESP8266,and I had a big interest in it and I made one immediately according to the article's step.The ESP8266 connected to a Network Time Protocol (NTP) server was cheaper to implement than using an RTC due to the discrepancies between the defined clock speed and actual clock speed.  You can see the picture,nixie tubes came into existence during the time of vacuum tubes and before LEDs (at least in the context of the Soviet Union). Once LED technology made its way into the USSR, nixie tubes began to fade out. Even today when shopping for nixie tubes online, all of the tubes I’ve purchased have been sent from either Russia or Ukraine. It seemed fitting that I would follow in history’s footsteps and switch over to the cheaper, easier and safer LED technology (I may or may not have shocked myself a few times on the 170VDC supply when testing).  I would like to use seven-segment displays to solve this problem. However,I think it's a little expensive even today. I would like to try something different, something that you don't really see sommercially. Suddently,binary clocks come to my mind,it's interested programmer like me. After a time of consideration, I sticked with a digital display and kept going back to the seven-segment variety. Using our OLED breakout allowed me to recreate the look of a 7-segment display, but I can add animations when the digits change. I added animations that make the individual segments drop in and fall off of the display when the time changes.In my nixie tube clock,I first tried using ESP8266 control both WIFI and the nixie tubes,but the WiFi stack was just too large to avoid seeing the multiplexed nixie tubes flicker any time the 8266 needed to do something WiFi-related. This meant that I had to have two controllers on the board; an ATmega328 would handle the nixies, and the ESP8266 would be responsible for the time and web GUI for settings. After that, I found ESP32 Thing from Sparkfun when I browse google, The ESP32 have two cores, one is to hanle the wifi stack and the other for programming. and I thought of my clock immediately and  how much easier it would be to just have one device to program and not worry about how I would transfer information between the two. About the Clock Stands  See the above picture,my clock is still work in progress currently,the code requires hard coding the SSID and password for the wireless access point. I really liked the web GUI I made, which I can access from the ESP8266 to change settings for the access point’s SSID and password or to select the NTP server location, time zone and whether or not to adjust for daylight saving time. I have two problems now. The one is that I haven’t been able to implement the GUI quite yet due to library changes in WiFi.h to serve web pages, and this is where I could use some help. If you’ve made a web server for your ESP32, please let me know how you handled multiple pages. I’ve been scratching my head throughout the build on how to get this done. With the ESP8266, there’s on(const String &uri, handler function), but that seems to have been removed on the ESP32. And the another problem with both clocks is how I handle daylight saving. Currently with the nixie clock, I have a selection box that removes an hour, but I would like to have that happen automatically. The NTP time returned will allow me to figure out the date, but given that daylight saving time begins on the second Sunday of March and ends on the first Sunday of November, how would you efficiently program in that functionality? The clock is far from finished, and aside from the problems I’ve mentioned above, there are some minor things I would like to touch up and a couple of extra features I’d like to add. And a part of my code is as following:#include <SPI.h>  // Include SPI if you're using SPI#include <TimeLib.h>#include <WiFi.h>#include <WiFiUdp.h>#include <SFE_MicroOLED.h>  // Include the SFE_MicroOLED library const char ssid[] = "************";  // your network SSID (name)const char pass[] = "************";  // your network password static const char ntpServerName[] = "time.nist.gov";const int timeZone = -6;  // Mountain Daylight Time WiFiUDP Udp;unsigned int localPort = 8888;  // local port to listen for UDP packets time_t getNtpTime();void sendNTPpacket(IPAddress &address); //IO Pin Constants//Digit 0#define PIN_RESET_0 12#define PIN_DC_0    22#define PIN_CS_0    13 //Digit 1#define PIN_RESET_1 17#define PIN_DC_1    22#define PIN_CS_1    16 //Digit 2#define PIN_RESET_2 4#define PIN_DC_2    22#define PIN_CS_2    0 //Digit 3#define PIN_RESET_3 2#define PIN_DC_3    22#define PIN_CS_3    15  //7-Seg Pixel Constants for OLED#define A_X 59#define A_Y 14 #define B_X 35#define B_Y 38 #define C_X 6#define C_Y 38 #define D_X 0#define D_Y 14 #define E_X 6#define E_Y 7 #define F_X 35#define F_Y 7 #define G_X 29 #define G_Y 14 //Initialize DisplaysMicroOLED oled0(PIN_RESET_0, PIN_DC_0, PIN_CS_0);MicroOLED oled1(PIN_RESET_1, PIN_DC_1, PIN_CS_1);MicroOLED oled2(PIN_RESET_2, PIN_DC_2, PIN_CS_2);MicroOLED oled3(PIN_RESET_3, PIN_DC_3, PIN_CS_3); bool updateTime=1;byte old_minute=0,old_hour=0; time_t prev = 0, prevNow=0; void setup() {  Serial.begin(115200);   //Setup Displays  oled0.begin();  oled0.clear(PAGE);  oled1.begin();  oled1.clear(PAGE);  oled2.begin();  oled2.clear(PAGE);  oled3.begin();  oled3.clear(PAGE);    // Connect to WiFi  WiFi.begin(ssid, pass);   pinMode(5,OUTPUT);  //Use the built in LED for WiFi Connection Status  bool state = 0;  while (WiFi.status() != WL_CONNECTED) {    delay(500);    Serial.print(".");    state = !state;    digitalWrite(5,state);  }  digitalWrite(5,HIGH);   Serial.print("IP number assigned by DHCP is ");  Serial.println(WiFi.localIP());  Serial.println("Starting UDP");  Udp.begin(localPort);  Serial.println("waiting for sync");  setSyncProvider(getNtpTime);  setSyncInterval(300);   //Display Current Time  Update_Digit(oled0,hourFormat12()/10,32);  Update_Digit(oled1,hourFormat12()%10,32);  Update_Digit(oled2,minute()/10,32);  Update_Digit(oled3,minute()%10,32);  prev = now();  prevNow = now()/60;} void loop() {  yield();  //Let the ESP32 handle the wifi stack   //Print the current time to Serial (debugging)  if(now() != prevNow)  {    prevNow = now();    Serial.print(hour());    Serial.print(' ');    Serial.print(minute());    Serial.print(' ');    Serial.print(second());    Serial.println();  }   //Only update when the minutes change  if(now()/60 != prev)  {    prev = now()/60;     //Update Display    for(byte i=0;i<33;i++)    {      if(hour() != old_hour)  //Does hour need to be updated?      {        if((hour()/10)!= old_hour/10) //Which hour digit needs to update? Both?        {          Update_Digit(oled0,hourFormat12()/10,i);          Update_Digit(oled1,hourFormat12()%10,i);        }        else  //Just update the first hour digit        {          Update_Digit(oled1,hourFormat12()%10,i);        }              }       if(minute() != old_minute)  //Does the minutes need to updated?      {        if((minute()/10)!= old_minute/10) //Which digit needs to be updated? Both?        {          Update_Digit(oled2,minute()/10,i);          Update_Digit(oled3,minute()%10,i);        }        else  //Just update the first minute digit        {          Update_Digit(oled3,minute()%10,i);        }              }      delay(5); //Wait 5ms to slow down the animations    }    old_hour = hour();    old_minute = minute();  }} //Animations for changing numbersvoid Update_Digit(MicroOLED &oled,byte number, byte i){  oled.clear(PAGE);  switch(number)  {    case 0:      if(i<17)      {        oled.rectFill(A_X+(64-i*4),A_Y,4,22); //A        oled.rectFill(A_X-(i*3.6),A_Y,4,22); //A        oled.rectFill(B_X,B_Y,22,4); //B        oled.rectFill(C_X,C_Y,22,4); //C        oled.rectFill(E_X+(32-i*2),E_Y,22,4); //E        oled.rectFill(F_X+(32-i*2),F_Y,22,4); //F        oled.rectFill(G_X-(i*4),G_Y,4,22); //G      }      else          break;     case 1:      oled.rectFill(A_X-(i*2),A_Y,4,22); //A      oled.rectFill(B_X,B_Y,22,4); //B      oled.rectFill(C_X,C_Y,22,4); //C      oled.rectFill(D_X-(i*2),D_Y,4,22); //D      oled.rectFill(E_X-(i*2),E_Y,22,4); //E      oled.rectFill(F_X-(i*2),F_Y,22,4); //F    break;    default:    break;  }  oled.display();}

Use of copper as a fluorescent material allows for the manufacture of inexpensive and environmentally compatible organic light-emitting diodes (OLEDs). Thermally activated delayed fuorescence (TADF) ensures high light yield. Scientists of Karlsruhe Institute of Technology (KIT), CYNORA, and the University of St Andrews have now measured the underlying quantum mechanics phenomenon of intersystem crossing in a copper complex. The results of this fundamental work are reported in the Science Advances journal and contribute to enhancing the energy efficiency of OLEDs.  Organic light-emitting diodes are deemed tomorrow's source of light. They homogeneously emit light in all observation directions and produce brilliant colors and high contrasts. As it is also possible to manufacture transparent and flexible OLEDs, new application and design options result, such as flat light sources on window panes or displays that can be rolled up. OLEDs consist of ultra-thin layers of organic materials, which serve as emitter and are located between two electrodes. When voltage is applied, electrons from the cathode and holes (positive charges) from the anode are injected into the emitter, where they form electron-hole pairs. These so-called excitons are quasiparticles in the excited state. When they decay into their initial state again, they release energy.Excitons may assume two different states: Singlet excitons decay immediately and emit light, whereas triplet excitons release their energy in the form of heat. Usually, 25 percent singlets and 75 percent triplets are encountered in OLEDs. To enhance energy efficiency of an OLED, also triplet excitons have to be used to generate light. In conventional light-emitting diodes heavy metals, such as iridium and platinum, are added for this purpose. But these materials are expensive, have a limited availability, and require complex OLED production methods.It is cheaper and environmentally more compatible to use copper complexes as emitter materials. Thermally activated delayed fluorescence (TADF) ensures high light yields and, hence, high efficiency: Triplet excitons are transformed into singlet excitons which then emit photons. TADF is based on the quantum mechanics phenomenon of intersystem crossing (ISC), a transition from one electronic excitation state to another one of changed multiplicity, i.e. from singlet to triplet or vice versa. In organic molecules, this process is determined by spin-orbit coupling. This is the interaction of the orbital angular momentum of an electron in an atom with the spin of the electron. In this way, all excitons, triplets and singlets, can be used for the generation of light. With TADF, copper luminescent material reaches an efficiency of 100 percent.Stefan Bräse and Larissa Bergmann of KIT's Institute of Organic Chemistry (IOC), in cooperation with researchers of the OLED technology company CYNORA and the University of St Andrews, United Kingdom, for the first time measured the speed of intersystem crossing in a highly luminescent, thermally activated delayed fluorescence copper(I) complex in the solid state. The results are reported in the Science Advances journal. The scientists determined a time constant of intersystem crossing from singlet to triplet of 27 picoseconds (27 trillionths of a second). The reverse process – reverse intersystem crossing – from triplet to singlet is slower and leads to a TADF lasting for an average of 11.5 microseconds. These measurements improve the understanding of mechanisms leading to TADF and facilitate the specific development of TADF materials for energy-efficient OLEDs.Reference:KY59-0202NYKY59-S101D2LCD-S301C31TR 

What if you could stick an OLED panel on your wall with a magnetic mat? A detachable OLED (organic light-emitting diode) panel that would just as easily be taken off as stuck on the wall? Reports surfaced on Tuesday that South Korea-based LG Display has fashioned just the thing, a 0.97 mm thick 55" flat OLED TV panel and only 1.9 kilos (4.2 pounds). LG Display showcased the screen in Korea.By comparison, LG Display's existing 55-inch OLED panel is 4.3 mm thick. Engadget's Jon Fingas said that "it raises the possibility of big-screen sets that easily blend into your living room's décor." That's the good news. The sad news is that there is no word about when such displays will make it to retail shops.The unveiling was part of a broader announcement to showcase the company's plans for the future, which center on OLED tech, said Don Reisinger in CNET. The screen was presented as one of the company's future displays at the media event. Using a magnetic mat, the screen can easily be stuck to—or removed from— a wall. To remove the display from the wall, said Reisinger, you peel the screen off the mat. The Yonhap News Agency report carried a photograph of a model gently lifting the detachable wallpaper OLED panel at the event in Seoul on Tuesday. Yonhap News Agency referred to the LG Display screen as a "wallpaper OLED panel." Don Reisinger of CNET referred to it as press-on wallpaper TV.Strategically, the unveiling tells us something about LG Display, said reports; the company appears to view high-end displays as a growth engine. (They released 55-inch, 66-inch and 77-inch OLED models earlier in the year, said Yonhap News Agency.) The showing also indicates that LG Display continues to focus attention on OLED.Reisinger offered reasons for why OLED "is widely believed to be the next frontier." He said, "The technology adds an organic compound layer that allows not only for exceedingly thin screens, but for those displays to be curved. The organic material also emits its own light, eliminating the need for a backlight. That allows for such thin screens and has made OLED a desirable choice not only for televisions, but for a wide range of wearables and other mobile products."While the wall-sticking panel is a delight to view, Ryan Waniata, writing in Digital Trends on Tuesday, expressed his view that "Such a display probably won't be used in a TV anytime in the near future; it's more likely to end up in wearable technology, automobile manufacturing, and commercial applications." Still, he added, "we could conceivably see such technology (paired with an outboard processing unit) becoming the TV of the future."  

Fujifilm Corporation and nano-electronics research institute imec have demonstrated full-color organic light-emitting diodes (OLED) by using their jointly-developed photoresist technology for organic semiconductors, a technology that enables submicron patterning. This breakthrough result paves the way to producing high-resolution and large organic Electroluminescent(EL) displays and establishing cost-competitive manufacturing methods.Organic EL displays are increasingly used for televisions, mobile devices including smartphones as well as wearable devices. Since they can be made thin and flexible, while also offering excellent response time and contrast ratio. It is said that today's products require organic EL displays of high pixel density, i.e. around 200ppi for 4K televisions, 500ppi for full HD mobile devices and even higher density for compact displays for wearable devices. There has been active R&D for organic semiconductors to develop a high-resolution patterning method for organic EL materials to be used in these products.In 2013, Fujifilm and imec jointly developed photoresist technology for organic semiconductors that enables submicron patterning without damaging the organic semiconductor materials, based on photolithography capable of high-resolution patterning on large substrates. There is no need for additional capital investment since an existing i-line exposure system can be used for the new technology. This is why the technology has attracted wide attention since the development announcement with anticipation of a cost-effective way of manufacturing high-resolution organic semiconductor devices.In the latest achievement, Fujifilm and imec produced full-color OLEDs with the photoresist technology for organic semiconductors and successfully verified their performance. Red, green and blue organic EL materials were patterned, each in the subpixel pitch of 20μm, to create full-color OLEDs. An OLED array of 40 x 40 dots at the resolution of 640ppi was realized and illuminated with UV rays to confirm that red, green and blue dots separately emitted light. The emission of red, green and blue lights was also confirmed in a test involving the application of voltage rather than illumination, confirming its correct performance.These results open new opportunities, such as using the novel photolithography in a multiple patterning process. An example would be creating an OLED array that adds a fourth color to red, green and blue, as well as developing previously-unseen devices such as a new sensors that integrate OLED with the organic photodetector.This research result is to be presented at the SID Display Week, one of the world's largest international exhibitions for information displays, held in San Jose, California from May 31 to June 5, 2015.Since the commencement of joint research in November 2012, Fujifilm and imec have broken through the boundary of conventional technology to contribute to the progress of technology associated with organic semiconductors, e.g., developing the photoresist technology for organic semiconductors that enables the realization of high-resolution submicron patterns. The two companies will continue to undertake cutting-edge R&D involving semiconductor materials, process technology and system integration, thereby contributing to resolving challenges faced by the organic electronics industry.