Methylammonium Lead Tribromide Single Crystal Detectors towards Robust Gamma‐Ray Photon Sensing

Abstract

photo voltaics, perovskite solar cells have already exceeded 23% in power conversion efficiency in a short development period. [1][2][3][4] OMHPs have also become popular in many other optoelectronic applications, such as light-emitting diodes, [5,6] photodetectors, [7,8] and lasing applications. [9] Properties such as tunable band gaps, [10,11] low trap state densities, [12] and long carrier diffusion lengths make OMHPs a desirable material for a wide range of optoelectronic applications, as well as being a focus for other semiconducting device applications. [13,14] These fascinating optoelectronic properties have recently sparked a new interest for applications of OMHPs for high-energy radiation detectors, which are considered as a critical technology in many fields, including nuclear safeguards, nuclear forensics, and astrophysics. Notably, current solid-state detector technologies using classical semiconductors have many challenges that must be overcome for wide spread development. For example, Cadmium Zinc Telluride (CZT) is a commercial γ-ray detection semiconductor achieving reasonable resolution (≈2% at 662 keV) at room temperature. However, the complicated and costly high-quality crystal growth for this semiconductor fabrication prohibits its broad adaptation. Another example of a more cost-effective semiconductor is high purity Germanium, (HPGe) which achieves an impressive resolution, (≈0.2% at 662 keV) albeit under operation at liquid nitrogen temperatures. [15] Thus, achieving cost efficient, robust high resolution detection at ambient conditions has been a long-time aim for semiconductor γ-ray detectors. In this arena, lead-halide based perovskites have been proposed as a new generation semiconductors in γ -spectroscopy for its low-cost solution process and simple crystal growth for room temperature detectors. [16][17][18] The incorporation of high-Z elements (i.e., Pb) underscores the opportunity for enhanced photoelectric interaction probability. Large band gaps and high resistivities are also essential for highly sensitive operation in the resistive mode. [19] Moreover, the long carrier lifetime and decent ambipolar mobility give great potential for single photon counting and pulse mode radiation sensing. [15] Previous reports have shown promising proof-of-principle results for the application of perovskites as ionizing radiation In recent years, hybrid perovskite single crystalline solid-state detectors have shown promise in γ-ray spectroscopy. Here, the γ-ray photon induced electrical pulses are investigated, which are produced by perovskite solid-state detectors made with the commonly used methylammonium lead tribromide crystals with chlorine incorporation. Under low electric field detector operation, slow pulses generated by γ-rays with average rise times of 65 µs are observed, which decreases to 20 µs when a higher electrical field of 500 V cm −1 is applied. However, the baseline becomes noisy quickly, which prevents collection of clean pulses for spectra construction. Further, by systematic...

Ion Migration Controlled Stability in α-Particle Response of CsPbBr2.4Cl0.6 Detectors

“…Although great achievements have been made in these previous works, there remains a major challenge for halide perovskite devices to obtain stable radiation spectra. On the basis of the halide perovskite single crystals, such as Cs 0.1 FA 0.9 PbI 2.8 Br 0.2 , MAPbBr 2.94 Cl 0.06 , CsPbBr 3 , − MAPbBr 3 , , and MAPbI 3 , the detectors demonstrated high energy spectral resolution of γ-rays or α-particles at room temperature. These successes were dependent on the complex and delicate designs of the materials and devices.…”

Recent Progress on the Performance of Lead‐Based Halide Perovskite APbX3 Detectors

“…As one of the most popular materials applied in γ-ray detector, CdZnTe is also hindered by high cost and poor crystal quality. [78,79] In recent years, lead-based halide perovskite compound APbX 3 has been reported for many times d) Power-dependent responsivity, external quantum efficiency, and detectivity of the device with the irradiance power densities varying from 0.09 to 1.53 mW cm À2 using 365 nm UV light. Reproduced with permission.…”

“…As one of the most popular materials applied in γ‐ray detector, CdZnTe is also hindered by high cost and poor crystal quality. [ 78,79 ] In recent years, lead‐based halide perovskite compound APbX 3 has been reported for many times in the application of X/γ‐ray detectors due to its high and balanced carrier mobility, long carrier diffusion length, low trap density, and low cost. [ 80–83 ]…”

Gamma‐Ray Radiation Stability of Mixed‐Cation Lead Mixed‐Halide Perovskite Single Crystals

“…[ 14–16 ] Furthermore, perovskites have also been regarded as a promising material for direct detection of high‐energy rays such as alfa‐ray, beta‐ray, X‐ray, and gamma‐ray owning to the appropriate bandgap, the high mobility‐lifetime product ( µτ ), the low‐cost crystal growth technology, and the large stopping power afforded by the high‐Z elements of Pb and halogen in the crystal structure. [ 17–24 ] Despite these extraordinary potentials, however, the practical application of perovskites in both space photovoltaic and high‐energy ray detector still faces the bottleneck due to the radiation‐induced instability.…”