Novel high-performance SOI junctionless FET-based phototransistor using channel doping engineering: Numerical investigation and sensitivity analysis

In this paper, graded channel doping (GCD) and junctionless paradigms are proposed as a new ways to improve the optical controlled field effect transistor (OCFET) and bridging the gap between the high responsivity and ultra-low power consumption. A careful mechanism study based on numerical investigation and a performance comparison between the proposed structure and both the conventional inversion mode (IM-OCFET) and the junctionless (JL-OCFET) designs is presented. It is found that the graded channel doping feature can efficiently improve the overall device optical and electrical performances. Moreover, the proposed design exhibits superior device figures of merit (FoMs) and provides ultra-sensitivity behavior as compared to both the conventional IM-OCFET and the JL-OCFET counterparts. Our investigation reveals also the outstanding capability of the proposed structure for offering the weak signal detection advantage that demonstrates the unique property of our phototransistor with GCD aspect. These characteristics not only underline the excellent switching behavior of the proposed design but also demonstrate the ability for overcoming the trade-off between the low cost and readily fabrication process in addition to ultrasensitive aspect with low power consumption. This makes the proposed GCD-JL-OCFET a potential alternative for developing low power communication systems.