MgZnO High Voltage Thin Film Transistors on Glass for Inverters in Building Integrated Photovoltaics.

Wen-Chiang Hong,Rui Li,Chieh-Jen Ku,Guangyuan Li,Pavel Reyes,Siamak Abbaslou,Yicheng Lu,Ming Lu,Szu-Ying Wang,Kuang Sheng

doi:10.1038/srep34169

Abstract

Building integrated photovoltaics (BIPV) have attracted considerable interests because of its aesthetically attractive appearance and overall low cost. In BIPV, system integration on a glass substrate like windows is essential to cover a large area of a building with low cost. However, the conventional high voltage devices in inverters have to be built on the specially selected single crystal substrates, limiting its application for large area electronic systems, such as the BIPV. We demonstrate a Magnesium Zinc Oxide (MZO) based high voltage thin film transistor (HVTFT) built on a transparent glass substrate. The devices are designed with unique ring-type structures and use modulated Mg doping in the channel - gate dielectric interface, resulting in a blocking voltage of over 600 V. In addition to BIPV, the MZO HVTFT based inverter technology also creates new opportunities for emerging self-powered smart glass.

Highlights

To solve this problem, and to optimize each individual solar panel, the micro-inverter technology[3] has been proposed to embed inverters into each photovoltaic module
To address these two major issues, we have explored the possibility of creating new inverters which can be integrated with solar modules to form a photovoltaic system on glass (PV-SOG)
Its low mobility, poor long-term stability, and the degradation at higher temperatures basically exclude its application in PV-SOGs, which operate under sunlight radiation, and its lifetime, like the regular residential solar cells, is expected to be more than 25 years

Summary

Introduction

To optimize each individual solar panel, the micro-inverter technology[3] has been proposed to embed inverters into each photovoltaic module. The interface between the gate dielectric (SiO2) and the MZO channel is specially designed by modulation-doping Mg into MZO to significantly increase the TFT blocking voltage This MZO based HVTFT on glass technology naturally fits the PV-SOGs, which are suitable for BIPV and promising for the self-powered smart glasses[27]. It may create opportunities for other high voltage applications, such as high dc voltage sensing[28], high-speed printers[29], flat-panel x-ray imaging systems for medical radiology[30], and space engineering[31]

Methods

Results

Conclusion