Besides its high stability, CsPbBr 3 possesses interesting electronic and optoelectronic properties such as high attenuation above the band gap, good photoresponse, large electron and hole mobility, long lifetimes, low excitation binding energy, halogen self-passivation, defect tolerance, luminosity, etc. [1,4-11] Device-quality single crystals have been prepared using a number of methods including a high-temperature process, [4] solution-based methods such as antisolvent vapor crystallization (AVC), [7,8,10] and inverse temperature crystallization. [12] The carrier concentration (holes) of these crystals varies in the range of 5 × 10 7 to 1 × 10 8 cm −3[9,10] and about 1 × 10 9 cm −3 for electrons, [9] resulting in nearly intrinsic crystals with resistivities in the range of 1-3 GΩ cm. [10] As a reference, Bridgmangrown crystals show resistivities as high as ≈340 GΩ cm [4,13] and mobility-lifetime (μτ) product for electrons and holes in the range of 1.7 × 10 −3 to 4.5 × 10 −4 cm 2 V −1 and 1.3 × 10 −3 to 9.5 × 10 −4 cm 2 V −1 , respectively. [4,14,15] These μτ values are better than that of CdZnTe (CZT) and CdTe. It is important to note that the electron μτ product of CZT and CdTe [4,11] is in the lower range of the corresponding values for CsPbBr 3 while the hole μτ product is only 0.1% that of CsPbBr 3. [4] The reported use of CsPbBr 3 for radiation sensing is limited to single crystals, except for its use as a thin film in X-ray scintillators. [1,3] There are no reports for direct radiation detection using thin-film diodes based on CsPbBr 3. This is related to the lack of deposition techniques for thick CsPbBr 3 films. The close space sublimation (CSS) process reported here addresses this problem. Although the intrinsic phase purity and crystal quality of single crystals offer improved optoelectronic properties, the high cost of the single crystal approach renders this option nonviable for portable and large-area applications, hence thin films are a better option. Furthermore, the photon attenuation coefficient of CsPbBr 3 is linear and comparable to that of CZT for energies up to 1000 keV, [4] but no exhaustive studies exist for the interaction of CsPbBr 3 with charged particles (α, β, etc.) or for higher photon energies such as gamma rays. The interaction of CsPbBr 3 2D nanosheets with ionizing radiation has been reported recently showing scintillation performance comparable to commercial crystals. [1] The observed The majority of solid-state radiation sensors are predominantly single crystals. However, for low-cost and large-area device applications, thin films are a better option. The first evidence of neutron detection using a Gallium Oxide/Cesium Lead Bromide (Ga 2 O 3 /CsPbBr 3) solid-state diode enabled by an innovative close space sublimation (CSS) method that allows deposition of thick CsPbBr 3 films is demonstrated. Furthermore, indirect neutron sensing is achieved using a 10 B layer for diodes biased at voltages as low as-5 V, showing the potential for low-power operation. The neutron response is ...
