Micro-engineered CH$_3$NH$_3$PbI$_3$ nanowire/graphene phototransistor for low intensity light detection at room temperature

TL;DR

This paper introduces a novel hybrid phototransistor combining methylammonium lead iodide nanowires with graphene, achieving extremely high responsivity at room temperature for low-light detection.

Contribution

First demonstration of a hybrid MAPbI$_3$ nanowire/graphene phototransistor with unprecedented responsivity in the visible spectrum.

Findings

Responsivity up to ~2.6 million A/W in visible light

Potential for room-temperature single-electron detection

Enhanced performance due to nanowire-graphene hybrid structure

Abstract

Methylammonium lead iodide perovskite has revolutionized the field of third generation solid-state solar cells leading to simple solar cell structures1 and certified efficiencies up to 20.1%. Recently the peculiar light harvesting properties of organometal halide perovskites have been exploited in photodetectors where responsivities of ~3.5 A/W and 180 A/W have been respectively achieved for pure perovskite-based devices and hybrid nanostructures. Here, we report on the first hybrid phototransistors where the performance of a network of photoactive Methylammonium Lead Iodide nanowires (hereafter MAPbI$_3$NW) are enhanced by CVD-grown monolayer graphene. These devices show responsivities as high as ~2.6x10$^6$ A/W in the visible range showing potential as room-temperature single-electron detector.