2D Simulation Study of p-type TFTs with Chemically Deposited Poly-PbS Active Channel



 In this work, the two-dimensional (2D) numerical simulation of p-type poly-PbS

TFT electrical characteristics are performed using a physically based device

simulator Atlas/Silvaco. The analytical expressions of defect density models

for acceptor- and donor-like traps are dened for poly-PbS thin lm material

deposited with chemical bath deposition technique. The parameters of defect

density model are optimized based on Levenberg-Marquardt algorithm to t

simulated and experimental results of TFTs. It is shown that the spatially uniform

density of defect states method used for trapped charge evaluation in Atlas

gives good agreement between simulated and experimental characteristics. An

important presence of deep (Gaussian) acceptor- and donor-like density of states

in poly-PbS band gap is conrmed. By controlling cation (donor-like) and anion

(acceptor-like) vacancies of poly-PbS lms could improved the performance of

p-type TFTs.


thin film transistor; simulation; density of states; optimization; defects; chemical bath deposition

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