Test on the Output Characteristics of Fe-β-Ga₂O₃Photoconductive Semiconductor Device Toward High-Power Microwave Sources

We focus on the Fe-β-Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>2</roman></sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>3</roman></sub> photoconductive semiconductor device (PCSD) for high-power microwave source applications. We tested and analyzed the output characteristics of this device, including its dark-state resistance (10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>13</roman></sup>Ω<roman xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">)</roman>, dark-state withstand voltage (31.6 kV), photoconductive output, and high-frequency response. When irradiated by single-pulse lasers at 532 and 1064 nm, both with a full-width at half-maximum (FWHM) of 10 ns, the Fe-β-Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>2</roman></sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>3</roman></sub> PCSD operates in a linear mode. The peak voltage output under 532 nm laser irradiation is 18 times that under 1064-nm laser irradiation. However, its photoresponsivity is relatively low, with the highest value only reaching the order of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> A/W. Under the irradiation of 532 nm continuous laser pulses with a base width of 30 ns at different modulation frequencies ranging from 0.4 to 1.2 GHz, the modulation depth of the Fe-β-Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>2</roman></sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>3</roman></sub> PCSD is above 90%. To further enhance the photoresponsivity, we carried out simulation-based optimizations on internal and external quantum efficiency. As a result, the photoresponsivity was increased by 6.97 times and 2.69 times, respectively.