Unipolar gate field enhanced photoresponse in organic layered halide perovskites.

Layered organic halide perovskites exhibit better chemical and structural stability than its bulk counterparts. Strong exciton binding also promotes excellent light-matter interaction with the possibility to tune the emission position using halide atom interchange. Despite excellent physical properties, the reported light sensitivity is lower than those of other material systems, largely ascribed to poor in-plane carrier transport and efficient recombination processes. Here, we show that large area CVD grown layered PEA2PbI4 can show an enhanced photoresponse with strong exciton resonance enhancement. The device exhibits gate-field sensitivity with a 1.5-fold enhancement at negative gate fields achieving a responsivity of 0.52 mA W-1 at the exciton position (520 nm). These results show that the layered perovskite with simple large area deposition shows excellent promise in optoelectronic device applications.