Releasable High-Performance GaAs Schottky Diodes for Gigahertz Operation of Flexible Bridge Rectifier

Novel strategies for printed electronic devices have rapidly evolved, particularly using thin films of inorganic semiconductors for high-performance. As one of the basic electronic components, diodes provide important functionalities in circuits, such as high-frequency switching and rectifying. In this report, the fabrication of releasable radio frequency (RF) gallium arsenide (GaAs)-based Schottky diodes is presented. This technique yields thousands of fully formed diodes with uniform performance densely packed onto a wafer piece, where each diode is released and transferred using a micro-stamp only when needed. Such production technique not only reduces material cost, but also benefits design efforts, as circuit designing often requires iterative designs with incremental changes. With low forward voltage and fast switching action, these printable forms of Schottky diodes are operable at microwave frequencies for diverse circuit applications. A full wave bridge rectifier, popularly used for RF-to-direct current (DC) converting circuit in wireless power transmission, is fabricated on a flexible substrate using four printed Schottky diodes. The results reveal successful RF-to-DC conversion with efficiency of up to 36.4% at principle frequency bands of mobile electronics, including cellular networks, Bluetooth, and Wi-Fi. The methods presented in this work form a simple yet robust path toward advanced high-performance flexible electronics.