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 Ga
₂
O
₃
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
₂
O
₃
. Based on this ZrGaO film, a deep-ultraviolet photodetector was fabricated, which has an ultrahigh photo-to-dark ratio up to 10
⁴
and a high responsivity (0.035 A/W at 0 V bias). The proposed idea of preparing bandgap tunable ZrGaO film by alloying ZrO
₂
with Ga
₂
O
₃
is of great significance to the bandgap engineering of Ga
₂
O
₃
and to its application in ultraviolet detection.