Suppression of peritectic reaction and PbSe-assisted growth of PbGa₂Se₄ single crystals for room-temperature radiation detection

Nuclear radiation detection technology holds significant application value in fields such as national security, medical imaging, and high-energy physics. However, the semiconductor material systems that meet high-performance requirements are still quite limited, and there is an urgent need to explore new candidate materials. PbGa₂Se₄, with an orthorhombic Fddd space group structure, a density of approximately 6.16 g/cm³, and a band gap of about 2.3 eV, possesses excellent radiation shielding capability and good carrier transport stability, making it a highly promising room-temperature radiation detection material. Nevertheless, the lack of large-sized and high-quality single-crystal preparation technology has severely hindered the in-depth fundamental research in key application fields such as radiation detection. In this paper, a large-sized PbGa₂Se₄ single crystal was successfully grown from the PbSe solution for the first time. Differential thermal analysis confirmed a peritectic reaction at 780 °C, leading to the design of a PbSe-assisted flux growth route. The as-grown crystal exhibited the band gap of 2.29 eV and a high resistivity of 2.96 × 10¹³ Ω·cm. A metal–semiconductor–metal (MSM) structured detector based on the crystal demonstrated a sensitivity of 60.06 μC·Gy⁻¹·cm⁻² under 50 kVp X-rays and an α-particle energy resolution of 55%, corresponding to an electron μτ product of 1.38 × 10⁻⁵ cm²·V⁻¹. These findings highlight PbGa₂Se₄ as a promising semiconductor candidate for room-temperature radiation detection.