Spatial Electrode Modulation Strategy for the Perovskite Single Crystal Photodetector

Perovskite meets the diverse needs of photodetectors (PDs) with excellent material properties and wealth of tuning capabilities. Herein, proposed by the spatial electrode modulation strategy, two kinds of perovskite PDs were designed and fabricated, which can modulate the detection bands and enhance the spectrum response greatly. For the light window electrode perovskite PDs, the asymmetric electric field can enhance the carrier collection efficiency and unravel the trade-off between high response and narrowband of PDs, exhibiting both high spectral selectivity (full width at half-maximum <14 nm) and high external quantum efficiency (EQE) of 78.5% at 570 nm. For the dot electrode structure PDs, broadband detection is achieved, attributing to the local electric field enhancement effect, achieving extra avalanche gain with a high EQE of 300% and faster response time of about 42 μs. Furthermore, we developed a packaging process for perovskite devices that enables their direct use in a humid environment. The proposed spatial electrode modulation strategy introduces a novel design paradigm for perovskite optoelectronic devices, paving the way for broader applications.