Hard X-ray Detector Based on p-Si/i-MgO/n-TiO₂ Heterojunction

Wide bandgap semiconductor-based directconversion X-ray detectors present a multitude of benefits and hold significant promise for various applications. In this study, a direct-conversion X-ray detector utilizing a p-Si/i-MgO/n-TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> structure was fabricated using radio frequency magnetron sputtering. The X-ray detection properties of the device were systematically investigated. This device achieved a signal-to-noise ratio and sensitivity of 58.75 and 1048.6 nC/(Gy<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">air</inf>•cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>), respectively, under a 6 MV hard X-ray and a bias voltage of -1 V, which was 359% and 273% higher than the p-Si/n-TiO2 structure devices. Furthermore, the p-Si/i-MgO/n-TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> X-ray detector has a faster response time of 0.11 s (rise) and 0.04 s (decay). These results provide new ideas for the subsequent development of highperformance wide-bandgap semiconductor hard X-ray detectors.