Bandgap Engineering of ZrGaO Films for Deep-Ultraviolet Detection
Jianmiao Guo, Minghe Ma, Yuqiang Li, Dan Zhang, Yanghui Liu, Wei Zheng
Abstract
In this letter, we successfully prepared tunable bandgap ZrGaO films on n-GaN substrates by RF magnetron sputtering. ZrGaO films with different Zr contents were successfully prepared with Zr target sputtered with various RF powers and Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> target sputtered with an RF power of 100 W. The bandgap of ZrGaO film deposited with a Zr target sputtering power of 70 W was broadened to 5.4 eV, indicating that Zr can be a promising candidate to enlarge the bandgap of Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . Based on this ZrGaO film, a deep-ultraviolet photodetector was fabricated, which has an ultrahigh photo-to-dark ratio up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> and a high responsivity (0.035 A/W at 0 V bias). The proposed idea of preparing bandgap tunable ZrGaO film by alloying ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> is of great significance to the bandgap engineering of Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and to its application in ultraviolet detection.