Poly(amic acid)-Polyimide Copolymer Interfacial Layers for Self-Powered CH₃NH₃PbI₃ Photovoltaic Photodiodes.

Area of Science:

• Materials Science
• Optoelectronics
• Renewable Energy

Background:

• Hybrid organohalide perovskites are key materials for high-efficiency photovoltaic (PV) devices.
• Perovskite-based photovoltaic photodiodes (PVPDs) are crucial for optoelectronic applications.
• Interface engineering is vital for optimizing PVPD performance by minimizing carrier recombination.

Purpose of the Study:

• To develop a highly sensitive, self-powered perovskite-based PVPD using a novel interfacial layer.
• To investigate the impact of a poly(amic acid)-polyimide (PAA-PI) copolymer interfacial layer on PVPD performance.
• To enhance the power conversion efficiency (PCE) and specific detectivity of methylammonium lead iodide (MAPbI3) PVPDs.

Main Methods:

• Fabrication of MAPbI3 PVPDs with and without a PAA-PI interfacial layer between the perovskite absorber and PEDOT:PSS hole injection layer.
• Characterization of PVPD performance, including power conversion efficiency (PCE), specific detectivity, linear dynamic range, and response times.
• Analysis of the PAA-PI layer's role in suppressing carrier recombination at the interfaces.

Main Results:

• The PAA-PI interfacial layer improved the PCE of MAPbI3 PVPDs from 10.4% to 11.8%.
• Specific detectivity was significantly enhanced by 49 times, reaching 7.82 × 10^10 Jones, compared to reference devices.
• The PAA-PI-passivated PVPD demonstrated a wide linear dynamic range (~103 dB) and fast response times (61 µs rise, 18 µs decay).

Conclusions:

• The PAA-PI interfacial layer effectively suppresses carrier recombination, leading to improved PVPD performance.
• Advanced interfacial engineering with PAA-PI layers is a promising strategy for high-performance, self-powered perovskite photodetectors.
• The developed PVPD shows potential for sensitive weak-light detection in various optoelectronic applications.