Efficient Gate-Tunable Hot-Carrier Photocurrent from Perovskite Multiple Quantum Wells

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Hot-carrier relaxation above the bandgap causes significant energy loss in devices.
• Efficient extraction of hot carriers is crucial for hot-carrier photocurrent generation.
• Metal-halide perovskites offer potential for hot-carrier applications.

Purpose of the Study:

• To observe long-lived hot carriers in perovskite multiple quantum wells.
• To demonstrate effective hot-hole photocurrent generation using 2D MoS₂ as an extraction layer.
• To investigate the enhancement of photocurrent efficiency via gate electric field application.

Main Methods:

• Fabrication of (BA)₂(MA)n-1Pb nI 3n+1 (n = 3) perovskite multiple quantum wells.
• Integration with 2D MoS₂ as a hot-carrier extraction layer.
• Operando transient reflection measurements and Density Functional Theory (DFT) calculations.

Main Results:

• Observation of long-lived hot carriers in perovskite quantum wells.
• Achieved external quantum efficiency (EQE) of up to 35.4% for short-circuit hot-carrier photocurrent.
• Enhanced EQE to 61.9% with applied gate electric field, alongside improved open-circuit photovoltage.
• Validated hot-hole extraction through wavelength, carrier density, and gate voltage-dependent measurements.

Conclusions:

• Perovskite multiple quantum wells are promising for generating long-lived hot carriers.
• 2D transition metal dichalcogenide semiconductors efficiently extract hot carriers.
• The developed device architecture holds potential for low-power optoelectronic applications.