Affiliation:
1. School of Physics Northwest University Xi ‘an 710127 China
2. College of Engineering Physics Shenzhen Technology University Shenzhen 518118 China
3. Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China
4. Department of Physics Department of Materials Science and Engineering and Department of Biomedical Engineering City University of Hong Kong Tat Chee Avenue Kowloon 999077 Hong Kong China
5. Key Laboratory of Opto‐Electronics Information Technology (Tianjin University) Ministry of Education School of Precision Instruments and Opto‐Electronics Engineering Tianjin University Tianjin 300072 China
Abstract
AbstractVisible‐blind ultraviolet (VBUV) photodetectors are designed for UV detection without responding to visible light, thus having many applications in communications, flame detection, environment monitoring, and astronomy. Herein, an organic device concept based on the bulk heterojunction (BHJ) photodiode is presented for high‐performance VBUV photodetection and imaging. The BHJ, comprised of an organic electron donor, 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT), and an electron acceptor, indene‐C60 bisadduct (ICBA), shows efficient generation and transport of free charges upon UV irradiation. The organic photodiode (OPD) delivers exceptional VBUV photodetection performance. At a low voltage of −0.5 V, the device exhibits a wide linear dynamic range of 98.15 dB. Furthermore, the OPD can detect ultra‐low light intensities down to 0.58 µW cm−2 with a high photoresponsivity of 0.12 A W−1 and specific detectivity of 2.75 × 1012 Jones. More importantly, by integrating the OPD with a readout integrated circuit, the pixel‐array organic VBUV imager is demonstrated to have high‐quality imaging capability. The results reveal a novel strategy to design VBUV photodetectors and imagers with balanced performance, cost, area, flexibility, and power consumption.
Funder
National Natural Science Foundation of China