Our group has developed an electrochemical UV sensor utilizing carbon quantum dots as the photoactive material functionalizing a graphene semiconductor layer. When used as a photoactive electrode in contact with a solid polymer electrolyte in a photoelectrochemical cell, illumination under UV radiation at 365 nm induces a photocurrent with a corresponding change in device voltage. The time-dependent change in voltage is a function of UV radiation intensity. Varying the UV LED power density from 26.6 mW/cm² (approximately 100% intensity) to 5.1 mW/cm² (approximately 20% intensity) results in time-dependent potential changes (dU/dt) ranging from approximately 4.0 mV/s to 0.5 mV/s. The dU/dt vs. LED power density trend is nearly linear (r² = 0.97). Similarly, when a constant bias potential is applied to the cell, a sustained photocurrent is observed under UV illumination, with the magnitude of the photocurrent a linear function of the LED power density. In that case, the coefficient of determination r² = 0.98. These results indicate that a graphene semiconductor, when functionalized with a photoactive material like carbon quantum dots, has application as a UV sensor with the ability to quantify the intensity of UV radiation.

中文翻译：

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使用碳量子点/石墨烯半导体的电化学紫外线传感器

我们的小组开发了一种电化学UV传感器，该传感器利用碳量子点作为功能化石墨烯半导体层的光敏材料。当用作光电化学电池中与固体聚合物电解质接触的光敏电极时，在365 nm的UV辐射下照射会产生光电流，并伴随着器件电压的变化。电压随时间的变化是紫外线辐射强度的函数。将UV LED功率密度从26.6 mW / cm ²（大约100％强度）更改为5.1 mW / cm ²（大约20％强度）会导致时间相关的电势变化（dU / dt）大约为4.0 mV / s至0.5毫伏/秒 该的dU / dt的相对于LED功率密度的趋势几乎是线性的（r ² = 0.97）。类似地，当向电池施加恒定偏置电势时，在紫外线照射下会观察到持续的光电流，光电流的大小与LED功率密度呈线性关系。在这种情况下，确定系数r ² = 0.98。这些结果表明，当石墨烯半导体被诸如碳量子点之类的光敏材料功能化时，它已被用作具有量化紫外线辐射强度的能力的紫外线传感器。