Programme

P.32 -- Poster, VCTP-49

Date: Wednesday, 31 July 2024

Time: 08:30 - 10:00

Investigating the damping states of drift velocity of electrons in GaAs semiconductor under the influence of external electric field

Nguyen Phuoc The (1,2), Le Thi Thu Thuy (2)

(1) Institute of Research and Development, Duy Tan University, 03 Quang Trung, Hai Chau, Da Nang, Viet Nam (2) Faculty of Environmental and Natural Sciences, Duy Tan University, 03 Quang Trung, Hai Chau, Da Nang, Viet Nam

This article presents the results of investigating the damping states of drift velocities of electrons in GaAs semiconductor with p-i-n structure using the Ensemble Monte Carlo (EMC) method under the influence of an external electric field. The selected device model has a pure semiconductor layer (i) in the middle with a size of several hundred nanometers, two semiconductor layers p and n on both sides with the same size chosen to be 20 nm, the photocarrier which was created by Ultra-fast laser pulses in the direction from p to i and then n layer with a concentration of about $10^18 cm-3$ Simulation results show that, when there is no external electric field, under the influence of the internal electric field due to the uneven distribution of carriers in the device, the velocity of electrons in the device is gradually damped, as observed in previous studies. With a specified size of the pure semiconductor layer, we used the external electric field as a control parameter. Gradually increasing the electric field every intervals of 20kV/cm resulted in a transition in the velocity state from under the damping to the crictical damping limit and then over the damping. Investigations with different sizes enabled us draw a phase diagram in the phase space between the critical electric field (EC) and the size (S) of the pure semiconductor layer. In addition, the research results also show that this critical electric field depends heavily on the concentration of the exciting carrier. The higher the temperature, the lower the critical electric field, while the higher the carrier concentration, the higher the critical electric field value. Keywords: Damped oscillation, EMC simulations, p-i-n structure, GaAs semiconductor

Presenter: Thùy Thị Thu Lê