Self-Powered MAPbI₃ Heterojunction Photodetector with Gradient-Level Electron Transport Layers and Dual...

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Electron transport layers (ETLs) are crucial for photodetector (PD) performance, influencing electron transfer and carrier recombination.
• Optimizing ETL energy levels can significantly enhance PD photoresponse and self-powering capabilities.

Purpose of the Study:

• To investigate the effect of ZnO ETL thickness on the performance of ITO/ZnO/CdS/MAPbI3/Spiro-OMeTAD heterojunction PDs.
• To explore the correlation between photovoltaic and pyroelectric responses and ZnO layer thickness.
• To achieve enhanced photoresponse and self-powering ability in PDs.

Main Methods:

• Fabrication of heterojunction PDs with varying ZnO ETL thicknesses (0-95 nm).
• Characterization of device performance, including responsivity and detectivity.
• Analysis of band arrangement and pyro-phototronic effects.

Main Results:

• The optimal ZnO thickness of 50 nm resulted in a responsivity (R) of 1.19 × 10^4 V/W and detectivity (D) of 2.22 × 10^9 Jones.
• Dual ETL layers significantly strengthened pyro-phototronic effects, enhancing device performance.
• The pyroelectric effect broadened the PD spectral range to 360-1550 nm.

Conclusions:

• Incorporating a ZnO ETL effectively improves the photoresponse and self-powering ability of heterojunction PDs.
• The ZnO layer thickness is critical for optimizing both photovoltaic and pyroelectric responses.
• The developed PD exhibits excellent performance and a wide spectral range due to enhanced pyro-phototronic effects.