Fast β-Ga₂O₃ Solar-Blind Photodetectors With High Detectivity on Sapphire Substrates

Ga2O3 Solar blind photodetectors (PDs) have been widely researched in recent years due to their ultrawide bandgap. In this work, high-quality <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga2O3 film with Full Width at Half Maximum (FWHM) of 0.19° was grown on sapphire substrates by MOCVD. The Ga2O3 Metal Semiconductor-Metal PDs were fabricated, showing a high response wavelength selectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1.89} \times {10} ^{{5}}$ </tex-math></inline-formula> (R<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text {250 nm}}$ </tex-math></inline-formula>/R<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text {400 nm}})$ </tex-math></inline-formula>. At 10 V, the PDs show responsivity (R) of about 500 A/W at 254 nm, specific detectivity (D*) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.7\times 10^{{14}}$ </tex-math></inline-formula> Jones, and response time of merely 1.5 ms, indicating its great potential for solar blind detection. Finally, images became unclear under illuminated light of about 178 nW/cm2 at 254 nm wavelength. These results open avenues for advanced Ga2O3-based optoelectronics.