35‐4: Carbon Nanotube Thin‐Film Transistors for Active‐Matrix Micro‐LED Display – Device Performances, Bias Stress Stability and Compact Modeling

Abstract

Carbon nanotube thin‐film transistor (CNT‐TFT) is expected to be a promising candidate for backplane technologies for emerging displays including micro‐LED, due to its extraordinary driving capability. In this work, CNT‐TFTs are characterized, which exhibit excellent on‐state current, high carrier mobility, and low subthreshold swing. Different from conventional TFTs, a positive threshold voltage shift under negative bias stress is observed in these devices. The mechanism is explored and explained, and an improved stretched‐exponential model is developed for such phenomenon. To predict the driving capability of CNT‐TFT backplane technology, compact models for CNT‐TFTs and micro‐LEDs are built based on experimental data, and SPICE simulation of a 3T1C pixel circuit is carried out. The results indicate that CNT‐TFTs enables high driving current in active‐matrix micro‐LED display with relative ease, paving the way for practical applications of CNT‐TFTs.