Chinese and South Korean scholars work together to develop a new generation of flexible image sensor materials

Recently, the team of Professor Wang Min and Professor Chen Yi Qing from Hefei University of Technology, cooperated with researchers at Sungkyunkwan University in Korea, prepared a large-grain non-layered nickel selenide thin film for the first time and built it into a photodetector array successfully. A new generation of flexible image sensor research and development provides a new method. The international academic journal "Advanced Materials" recently published the results.

Image sensors can convert optical images into electronic information and are widely used in electro-optical devices. The future of wearable smart devices requires that the image sensor be flexible and can be bent and folded. At present, the integrated image sensor which is widely used in digital cameras is difficult to meet the future demand because of its lack of flexibility. Current research suggests that flexible, low-dimensional materials are ideal candidates for silicon substrates.

Hefei University of Technology and South Korea Sungkyunkwan University recently formed a joint research team, proposed a new method of interface limited epitaxial growth, the successful preparation of high-quality large non-layered structure of nickel selenide thin film. Through the pattern growth of nickel selenide micron band array, they constructed a high performance and uniform light detector array, which laid the foundation for the realization of flexible image sensor.

According to reports, due to the microgranular grain size of the new material film, the grain boundaries between the grains are reduced, which significantly reduces the carrier scattering at the grain boundaries, thereby greatly improving the responsivity of the photodetector. The experimental results show that the photodetector prepared with high quality nickel selenide film based on micrometer-scale crystal grains can achieve a current of 150 A per watt of light, and its responsivity is increased by four orders of magnitude compared with that of the nanoscale grain film.