Low-Bias Weak Ambient Light Sensor Using Edge-Removed MISIM Device With High Sensitivity

In this study, an edge-removed (ER) metal-insulator–semiconductor-insulator–metal (MISIM) device is proposed for weak ambient light detection. The ER structure is employed to minimize dark current and enhance sensitivity. Also, the ER structure features the simplicity of fabrication and facilitates the removal of positive oxide charges, thereby eliminating the lateral currents induced by these charges. The simulation is also conducted to support the finding. As it comes to the advantages of the MISIM structure, it demonstrates exceptional light-sensing capabilities under both positive and negative biases. In addition, with the combination of both ER and MISIM structure, the device features a floating substrate and asymmetric concentric electrodes, achieving high sensitivity—1066 at 100 lux—while operating at a low voltage of 0.2 V, aligning with the trend toward reduced power consumption. In addition, the device maintains linearity in sensitivity across various light intensities and retains high sensitivity under low light conditions. This article concludes with benchmarks that highlight the superior performance of this device compared to other MIS-like photosensors.