CuInSe₂ Quantum Dots Hybrid Hole Transfer Layer for Halide Perovskite Photodetectors

A novel hybrid hole transport layer (HTL) of CuInSe₂ quantum dots (QDs)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was developed to enhance the performance of halide metal perovskite (MAPbI₃))-based photodetectors. The introduction of CuInSe₂ QDs not only improved the wettability of the PEDOT:PSS HTL for the growth of perovskite crystals but also facilitated the transportation of holes from the perovskite to the HTL. As a result, both responsivity and detectivity of the device were increased dramatically by CuInSe₂ QDs hybrid HTL, showing excellent photoresponsivity of 240 mA/W, larger ratio of photocurrent density to dark current density of 4.1 X 10⁶, fast on-off switching properties of <0.02 s, and remarkable detectivity values of 1.02 × 10¹³ Jones at 580 nm and above 5.01 × 10¹² Jones over the visible light region without an external bias voltage. In addition, the photodetectors also showed excellent thermal stability in the range of 10–110 °C. Therefore, a unique design idea of a hole transport material would be an anticipated direction for efficient halide metal perovskite-based devices.