Development of Organometallic Hybrid Perovskite Single Crystals towards Radiation Sensing and Optoelectronic Applications

Organometallic hybrid perovskites have shown great promise for many optoelectronic applications, such as photovoltaics, LEDs, photodetectors, lasing etc. Recently, single crystalline OMHP has been demonstrated as a cost-effective alternative to traditional, expensive inorganic semiconductors. In this perspective, MAPbBr₃ [Methylammonium lead tribromide] single crystals are focused towards development in efficient high-energy radiation detection. The growth, effects of growth conditions, device fabrication, and application results are presented here to discuss the challenges and solutions of these challenges for the material to be capable of high resolution radiation sensing. Inverse temperature crystallization techniques have been demonstrated as a simple growth method for high quality MAPbBr₃ single crystals. The ability to alter the growth conditions, such as precursor ratio and purity, to enhance the electronic properties of MAPbBr₃ single crystals is experimentally demonstrated, with bulk resistivity values up to 1 x 10¹⁰ Ω and trap densities on the order of 10⁸ - 10⁹ cm⁻³. The importance of electrode selection and interfacial engineering for improved performance is also discussed, where a Cr electrode gives a high interfacial resistance of 1.79 x 10⁹ Ω, compared to the low interfacial resistance of Au contacts giving a much lower interfacial resistance of 1.32 x 10⁷ Ω. The main challenge in this material is described by the imbalance of electron and hole charge transport properties. Doping of Cl^- is discussed in literature and experimentally demonstrated here to improve the electron transport in MAPbBr₃-based single crystals, via alpha particle radiation detection. Results to radiation sensing of alpha particles, gamma photons, and neutrons show promising results for MAPbBr₃ single crystals as a novel, cost-effective radiation sensing material under $10 cm^-3.