Micro-pixelated halide perovskite photodiodes fabricated with ultraviolet laser scribing

Abstract

In this study, we present a complex investigation for miniaturizing perovskite photodiodes (PPDs) in various geometries with the use of ultraviolet laser scribing (UV-LS). Employing a 355 nm (3.5 eV) pulsed laser at 30 kHz, we manufactured PPDs with pixel configurations of 70 × 130, 520 × 580, and 2000 × 2000 μm2. The utilization of UV-LS has a proven efficiency in achieving relevant diode characteristics, such as low dark currents and high shunt resistance, as well as ultrafast response. The multi-step scribing cycle provided precise patterning of PPDs in a string design. The dark current densities demonstrated exceptional uniformity, ranging from 10−10 A/cm2 for 2000 × 2000 μm2 pixelated PPDs to 10−9 A/cm2 for the 70 × 130 μm2 configuration. The string PPDs, consisting of 10 pixels per string, displayed homogenous dark current values, ensuring effective isolation between devices. Under green light illumination (540 nm), all PPD types exhibited a broad linear dynamic range (LDR). Specifically, LDR values reached 110, 117, and 136 dB for 70 × 130, 520 × 580, and 2000 × 2000 devices, respectively, spanning an illumination intensity range from 2 × 10−3 to 2 mW/cm2. High responsivity values up to 0.38 A/W, depending on the PPDs' geometry, highlight the potential of laser scribing devices for sensing in the visible range. The calculated specific detectivity performance (from 1011 to 1013 Jones) surpasses commercial analogs, while the sub-microsecond response of 70 × 130 and 520 × 580 μm2 miniaturized devices underscores their suitability for precise time resolution detection systems.