NIR self-powered photodetection and gate tunable rectification behavior in 2D GeSe/MoSe2 heterojunction diode

Two-dimensional (2D) heterostructure with atomically sharp interface holds promise for future electronics and optoelectronics because of their multi-functionalities. Here we demonstrate gate-tunable rectifying behavior and self-powered photovoltaic characteristics of novel p-GeSe/n-MoSe2 van der waal heterojunction (vdW HJ). A substantial increase in rectification behavior was observed when the devices were subjected to gate bias. The highest rectification of ~ 1 × 104 was obtained at Vg = − 40 V. Remarkable rectification behavior of the p-n diode is solely attributed to the sharp interface between metal and GeSe/MoSe2. The device exhibits a high photoresponse towards NIR (850 nm). A high photoresponsivity of 465 mAW−1, an excellent EQE of 670%, a fast rise time of 180 ms, and a decay time of 360 ms were obtained. Furthermore, the diode exhibits detectivity (D) of 7.3 × 109 Jones, the normalized photocurrent to the dark current ratio (NPDR) of 1.9 × 1010 W−1, and the noise equivalent power (NEP) of 1.22 × 10–13 WHz−1/2. The strong light-matter interaction stipulates that the GeSe/MoSe2 diode may open new realms in multi-functional electronics and optoelectronics applications.

PID Control for Temperature and Motor Speed Based on PLC

Transesterification process of used cooking oil to biodiesel need heating and mixing of ingredients and catalyst at temperature of 30-65oC and stirring speed of 700 rpm for 60 minutes. This research builds a prototype of biodiesel reactor control system to control those process automatically. The system is built using heater element, LM35DZ temperature sensor, DC motor to drive the stirrer, and rotary encoder sensor. PLC OMRON CP1E NA20DR-A is used as system controller by using PID algorithm. The results of this research shows that this system works well as expected. Test results of motor speed control shows, at 700 rpm set point this system gives stable response at 100 % Proportional band, 1,6 s Integral, and 0,2 derivative PID parameters, the system at this setting gives fast rise time and have small overshoot. Test result of temperature control shows, at 60oC set point this system works well at 1% proportional band, 400 s integral, and 0 s derivative PID parameters, the system at this setting gives fast rise time and stable steady state.