Quasi-Tandem Photodetector with Tunable Narrowband Response and Submicrosecond Response Time: Charge-Selected Transmitting Narrowing

Abstract

The development of tandem optoelectronic devices has garnered significant attention as they can potentially enhance the light absorption and power conversion efficiency of solar cells. A perovskite/interface layer/organic quasi-tandem system was constructed to develop a series of narrowband photodetectors (NPDs) that function in the visible and near-infrared regions. The range of narrowband response can be directionally modulated by adjusting the perovskite and organic material contents at the front and back subcells, respectively. This enables improvement in the selectivity and flexibility of the systems, which ultimately enhance the functional design of the devices. When the response peak was set to approximately 790 nm, the minimum full width at halfmaximum was recorded as 41 nm. Unlike the connecting middle layer in tandem solar cells, the interface layer in quasi-tandem NPDs can actively regulate the behavior of photo-generated carriers, leading to a significant reduction in the thickness of the active layer and transportation distance. Consequently, quasi-tandem NPDs respond at the submicrosecond scale, which is five times faster than the response times of photodetectors that are fabricated with thick photo-active films to passively regulate and decay carriers. This work provides a pioneering reference for the development of ultra-fast NPDs.