Photosensitive Complementary Inverters Based on n‐Channel MoS2 and p‐Channel MoTe2 Transistors for Light‐to‐Frequency Conversion Circuits

Photosensitive complementary inverters, composed of multilayered molybdenum disulfide (MoS2) and molybdenum ditelluride (MoTe2), are demonstrated for the applications that require low power consumption and excellent signal‐to‐noise ratio (SNR). The photosensitive characteristics of MoS2, along with the negligible photosensitivity of MoTe2, successfully render them applicable to the light‐to‐frequency conversion circuits that enable high SNR immunity. Under blue light‐emitting diodes (LEDs), the low noise margin and transition width for the voltage transfer characteristics in complementary inverters significantly improve from 1.29 to 1.49 V and 0.24 to 0.31 V, respectively, as compared with those of inverters in the dark. The experimental demonstration of photosensitive inverters and their electrical validations on proposed concepts, supported from SPICE (i.e., simulation program with integrated circuit emphasis) simulation, are systematically obtained, substantiating that this platform can be one of the core parts for future Internet of Things (IOT) applications, which simultaneously demand both ultralow power and robustness on security. For optical sensor applications, a high signal‐to‐noise ratio is highly required. To achieve better immunity on external noise in sensors, the light‐to‐frequency conversion circuit is one of the essential elements. Herein, photosensitive complementary inverters and ring oscillators, composed of multi‐layered n‐channel MoS2 and p‐channel MoTe2 field‐effect transistors, are successfully demonstrated. Experimental demonstration and their validation via SmartSpice simulation are presented.