Semitransparent near-infrared Sn–Pb hybrid perovskite photodetectors

Abstract

Perovskite photodetectors are a promising technology for imaging applications, due to their high performance, tunable absorption spectrum and large area processability. New applications require devices with properties such as transparency, near-infrared (NIR) absorption or scalability. Here, we have fabricated semitransparent NIR perovskite photodetectors based on tin–lead (Sn–Pb) hybrid perovskites, by using very thin film perovskite layers (200 nm) and transparent indium tin oxide (ITO) electrodes. The top ITO contact was processed via pulsed layer deposition (PLD) with no damage to the underlying stack. The photodetectors have a full stack transmission of over 48% in the NIR (between 780 and 1100 nm) and exhibit good performance with a dark current of 1.74 × 10⁻² mA cm⁻² (at −0.2 V), external quantum efficiency of 23% and 13%, and detectivity of 6.6 × 10¹⁰ and 4.2 × 10¹⁰ Jones (at −0.2 V), at 850 and 940 nm, respectively. The performance of these devices makes them good candidates to be used as photodetectors for NIR applications or as bifacial devices.