科研之友
微信
新浪微博
Facebook
分享链接
摘要
Photodetectors and imagers with short-wave infrared (SWIR) sensitivities at wavelengths beyond the bandgap of silicon (E-g similar to 1.1 eV) are currently subject to a rapidly expanding application space. Despite continued technological advancement, linear dynamic range and high costs associated with processing III-V semiconductors still limit their widespread usage. Solution-processed colloidal quantum dots (CQDs) - with tunable bandgap and strong light-matter interaction - are highly suitable as infrared absorbers for cost-effective photodetection. Here, we demonstrate a SWIR photodiode architecture with n-type zinc oxide (ZnO) nanomembrane and p-type lead sulfide (PbS) CQD thin film vertically stacked together. In the PbS CQD/ZnO nanomembrane p-n photodiode, the incident SWIR photons can be absorbed in the PbS CQD film and the photoexcited electron-hole pairs are rapidly separated by the built-in electric field. The fabricated heterojunction p-n photodiodes show a broad short-circuit photocurrent response with a peak responsivity of similar to 75 mA/W and a maximum linear dynamic range of similar to 100 dB. Finally, to demonstrate the uniformity and scalability, 16 x 16 photodetectors arrays (256 pixels) have been realized showing a very uniform photocurrent response with I-sc in the range of 100 nA. As the increased maturity of large-scale film fabrication of PbS CQD along with CMOS readout integrated circuit technology, focal plane arrays can be realized based on PbS CQD/ZnO nanomembrane heterostructures.
-
单位中国科学院; 华中科技大学; 中国科学院研究生院
