Bandgap Engineering of ZrGaO Films for Deep-Ultraviolet Detection

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 Ga2O3 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 Ga2O3. Based on this ZrGaO film, a deep-ultraviolet photodetector was fabricated, which has an ultrahigh photo-to-dark ratio up to 104 and a high responsivity (0.035 A/W at 0 V bias). The proposed idea of preparing bandgap tunable ZrGaO film by alloying ZrO2 with Ga2O3 is of great significance to the bandgap engineering of Ga2O3 and to its application in ultraviolet detection.