Research On Testing Technology And Equipment Of Photoelectric Characteristics For Flexible Light-emitting Devices

In recent years,flexible organic light-emitting diodes(OLEDs)have gained more and more extensive applications in smart phones,smart watches and other fields.It is expected that by 2023,more than 50% of smart phones will use flexible screens.The introduction of the flexible structure makes the mass production and use of the screen face more demanding requirements.On the one hand,we need to pay attention to the bending and twisting resistance of flexible display devices.On the other hand,the ambient temperature will also have an important impact on the performance of flexible display devices.We need to delve into the key factors that affect its performance and lifetime.Therefore,the development of high-performance bending and twisting photoelectric test equipment and flexible lightemitting device temperature-resistant test equipment is of great significance for studying the performance and aging characteristics of flexible light-emitting devices,and is also conducive to promoting the application and development of flexible displays..First of all,this paper independently developed a flexible display bending and twisting photoelectric characteristic test system for flexible devices(light emitting panel/display screen).The system is developed based on LabVIEW programming through integrate brightness meter,source meter,self-designed bending and twisting mechanical structure.The self-designed mechanical structure performs automatic bending at any angle within the range of 0 ? 270 ° and automatic twisting at any angle within the range of ± 90 ° to the flexible light-emitting samples.According to the user's preseted parameters,the test system can measure photoelectric parameters for samples through bending or twisting.The measured data can be saved after the test.We realize the integration of the bending and twisting device and the display performance testing device.It provides an automated test method for studying flexible display device's photoelectric characteristics of bending and twisting resistance,and it improves the detection accuracy and use efficiency.Then,a 4-channel high-temperature IVL test system for studying the photoelectric characteristics of OLED devices at high temperatures was independently developed.The test system is based on the LabVIEW development platform,which integrates and develops hardware such as self-design temperature control modules,brightness meters,source meters,motion modules,and CCD cameras.It can meet the requirements of setting different ambient temperatures for four devices and accurately controlling temperature or meet the need for IVL testing under different temperature conditions.The test system solves the problems that the thermostat is bulky,unable to heat each device individually,and unable to measure the real photoelectric parameters of the device during the temperature control of the device.Through experimental verification,the temperature control range of the system is from room temperature to 120?.The temperature accuracy within 10 hours of continuous temperature control is within 1?.It has the advantages of low cost,high reliability,easy expansion and accurate temperature control.On the basis of above 4-channel high-temperature IVL test system,we developed a 32-channel IVL and lifetime test system for studying OLED devices,which can provides lowtemperature control functions,multi-channel device power supply and automatic alignment of brightness meters.We creatively proposed a special solution for the high and low temperature control of OLED by combining semiconductor technology and test boxes.The system can set the high or low temperature environment simulation from-40 to 120? for 32 channels for each OLED devices,and the temperature control accuracy is within 1?.Furthermore,the power supply of the multi-channel power module and the automatic alignment function of the brightness meter enable each OLED device to be automatically tested at a specified temperature.The development of the test system provides a simple test method and special test equipment for people to research photoelectric characteristics under high and low temperature of the lightemitting device.And it has a certain role in promoting the research of the high and low temperature characteristics and the development of the environmental test equipment of the flexible display device.