Organic–inorganic halide perovskites (OIHPs) bring an unprecedented opportunity for radiation detection with their defect-tolerance nature, large mobility–lifetime product, and simple crystal growth from solution. Here we report a dopant compensation in alloyed OIHP single crystals to overcome limitations of device noise and charge collection, enabling γ-ray spectrum collection at room temperature. CH₃NH₃PbBr₃ and CH₃NH₃PbCl₃ are found to be p-type and n-type doped, respectively, whereas dopant-compensated CH₃NH₃PbBr_2.94C_10.06 alloy has over tenfold improved bulk resistivity of 3.6 × 109 Ω cm. Alloying also increases the hole mobility to 560 cm² V^-1 s^-1, yielding a high mobility–lifetime product of 1.8 × 10^-2 cm² V^-1. The use of a guard ring electrode in the detector reduces the crystal surface leakage current and device dark current. A distinguishable 137Cs energy spectrum with comparable or better resolution than standard scintillator detectors is collected under a small electric field of 1.8 V mm^-1 at room temperature.

Nature Materials (2017) doi:10.1038/nmat4927
Received 02 March 2017 Accepted 26 May 2017 Published online 03 July 2017

http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4927.html