Photoelectric Properties of GaSSe (0 ≤ ≤ 1) Layered Crystals.

In this study, the photoelectric properties of a complete series of GaSSe (0 ≤ ≤ 1) layered crystals are investigated. The photoconductivity spectra indicate a decreasing bandgap of GaSSe as the Se composition increases. Time-resolved photocurrent measurements reveal a significant improvement in the response of GaSSe to light with increasing . Frequency-dependent photocurrent measurements demonstrate that both pure GaS crystals and GaSSe ternary alloy crystals exhibit a rapid decrease in photocurrents with increasing illumination frequency. Crystals with lower exhibit a faster decrease in photocurrent. However, pure GaSe crystal maintains its photocurrent significantly even at high frequencies. Measurements for laser-power-dependent photoresponsivity and bias-voltage-dependent photoresponsivity also indicate an increase in the photoresponsivity of GaSSe as increases. Overall, the photoresponsive performance of GaSSe is enhanced with increasing , and pure GaSe exhibits the best performance. This result contradicts the findings of previous reports. Additionally, the inverse trends between bandgap and photoresponsivity with increasing suggest that GaSSe-based photodetectors could potentially offer a high response and wavelength-selectivity for UV and visible light detection. Thus, this work provides novel insights into the photoelectric characteristics of GaSSe layered crystals and highlights their potential for optoelectronic applications.