Planar-integrated single-crystalline perovskite photodetectors

TLDR

Hybrid perovskites are promising optoelectronic semiconductors, but morphological disorder limits performance, and single crystals offer low trap density, high mobility, and long diffusion length, making them ideal for fast, sensitive photodetection, yet they cannot be grown on planar substrates. We fabricate large‑area planar‑integrated films composed of large perovskite single crystals. The crystalline films exhibit single‑crystal–level mobility and diffusion length. These films enable a light detector with >10⁴ electrons per photon gain and >10⁸ Hz gain‑bandwidth product, outperforming other perovskite sensors.

Abstract

Abstract Hybrid perovskites are promising semiconductors for optoelectronic applications. However, they suffer from morphological disorder that limits their optoelectronic properties and, ultimately, device performance. Recently, perovskite single crystals have been shown to overcome this problem and exhibit impressive improvements: low trap density, low intrinsic carrier concentration, high mobility, and long diffusion length that outperform perovskite-based thin films. These characteristics make the material ideal for realizing photodetection that is simultaneously fast and sensitive; unfortunately, these macroscopic single crystals cannot be grown on a planar substrate, curtailing their potential for optoelectronic integration. Here we produce large-area planar-integrated films made up of large perovskite single crystals. These crystalline films exhibit mobility and diffusion length comparable with those of single crystals. Using this technique, we produced a high-performance light detector showing high gain (above 10 4 electrons per photon) and high gain-bandwidth product (above 10 8 Hz) relative to other perovskite-based optical sensors.