Micro-pixelated halide perovskite photodiodes fabricated with ultraviolet laser scribing

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.