Self‐Powered and Highly Efficient Ion‐Diffused MAPbBr 3 Perovskite Single Crystal‐Based UV–Vis Photodiode

The perovskite single crystals (PSC) produced by solution‐processed metallic ions doping have a thick p–n junction (greater than 10 µm). Meanwhile, to achieve high responsivity, the carrier drift length (µτE) has to be larger than the dimensions of the detector. If the p–n junction is quite thick, a high bias voltage is required. For the practical application of photodiode, it is imperative to find a means to generate a thin p–n junction. A productive technique is suggested for forming a thin p–n junction by diffusing metallic ions, resulting in a longer drift length of the carrier than the depletion width. Thinner p–n junction leads to reduced dark current density (0.5 µA cm −2 ), low trap density (5.71 × 10 8 cm −3 ), high mobility (417 cm 2 V −1 s −1 ), and hence increased responsivity (77.69 A W −1 ) for 30 µW cm −2 UV illumination under a low applied voltage of −15 V. A quick response time with a rise/fall duration of 22 ms/30 ms under 0 V and long‐term stability for over 3 months in ambient airis achieved. To comprehend the performance with the thinner p–n junction‐based photodiodes, the results under UV–Vis illumination are examined and compared. The outcomes hint at a method that holds promise for producing efficient photodiodes.