Optimization of Al doped ZnO thin films for flexible TFTs and Piezoelectric Sensors

Abstract

Flexible electronics, based on inexpensive processing and material systems, are becoming the new electronic growth paradigm, which will enable 'electronics everywhere' needed for IoT applications. In this thesis, ZnO based thin film electronics are studies and optimized for the targeted applications of flexible TFT and sensors. In the first part, the research focused on synthesis and modulating the electronic and mechanical properties of ALD based ZnO film through Al doping, deposition conditions and gas mix/flow based on DoE methodology. This included an in-depth physical analysis using XRD, AFM, SEM and micro Raman coupled with electrical and mechanical characterization to establish response-surface models for these observations. This was followed by physics-based explanation for these observations and results, succeeded by micro fabricating TFT and stress sensors test structures to conduct device level performance and endurance assessments. Through the optimized Al doped ZnO film, the fabricated devices and sensors have demonstrated excellent performance benchmarks, starting from record mobility, very high gauge factor and very long-time endurance and operation.

Date of Award	Dec 2017
Original language	American English