Photosensitive Characteristics of Ga₂O₃/p-Si Schottky Barrier Solar-Blind Photodetector

In this work, a 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>/p-Si MOS-type Schottky barrier photodetector was successfully fabricated and characterized for solar-blind ultraviolet detection. The electrical and optoelectronic characterizations of the devices were performed under dark and 254 nm illumination. The device performance metrics, including Schottky barrier height <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$( {{{\Phi }_{B0}}} )$</tex-math></inline-formula>, ideality factor <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$( n )$</tex-math></inline-formula>, and series resistance <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$( {{{R}_s}} )$</tex-math></inline-formula> were extracted employing Cheung’s method and Norde’s methods. Both methods revealed that UV illumination leads to reductions in the ideality factor and series resistance, indicating improved carrier transport and reduced recombination losses due to the generation of photo-induced carriers. In addition, under the 254 nm illumination and reverse bias of −5 V, the devices exhibited a maximum responsivity of 0.39 A/W and a corresponding external quantum efficiency (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$EQE)$</tex-math></inline-formula> of 193%. The noise-equivalent power (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$NEP$</tex-math></inline-formula>) and detectivity (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$D$</tex-math></inline-formula>) were 1.45×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−13</sup> W and 6.89×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> Jones, respectively, demonstrating the high sensitivity and potential of the 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>/p-Si Schottky structure for deep UV sensing applications.