Ultrahigh, ultrafast and large response size visible-near-infrared optical position sensitive detectors based on CIGS structures

Abstract

CIGS-based heterostructures have been demonstrated to achieve superior high absorption and photovoltaic effects theoretically and experimentally, making them extremely attractive for realizing optoelectronic devices. However, the applications of CIGS are mainly focused on solar cells. In this work, the lateral photovoltaic effect (LPE) is firstly observed in the CIGS film with a glass/Mo/CIGS/CdS/ZnO/ITO structure, indicating its great potential for application in position sensitive detectors (PSDs). LPE measurements reveal that this structured PSD exhibits ultrahigh sensitivity and excellent linearity even to a very large working distance of 28 mm in the visible-near-infrared range with the position sensitivity up to 431.6 mV mm⁻¹. Notably, the detector shows ultrafast response speed with a rise time of 8.3 μs and a fall time of 7.7 μs, and capability to work stably under air conditions for a very long time. The unprecedented performance could be attributed to the good quality of this CIGS structure, as well as the unique optical properties of the CIGS layer and the excellent conductivity of the ITO layer. These findings suggest that the glass/Mo/CIGS/CdS/ZnO/ITO structure has great potential for application in the field of visible-near-infrared optical position sensitive detection and might be used as elements for the construction of high-speed integrated optoelectronic sensor circuitry.