InGaP Photovoltaic Array Packaging Comparison

Renewable energy sources such as photovoltaic (PV), alphavoltaic (AV), and betavoltaic (BV) devices are semiconductor energy conversion devices that can provide energy for long periods of time and--in the case of AVs/BVs--can operate in extreme conditions. These compact power sources are uniquely qualified to support unattended remote sensors, early warning electronics, and unmanned systems that increase situational awareness and Soldier effectiveness with small quantities of distributed energy for mobility and duration. In this technical report, we describe the fabrication and packaging process development of InGaP PV devices for both single-cell and four-cell InGaP devices in a series-wired quad array to match the voltage of conventional Li-ion batteries for the purpose of recharge. Current-voltage (IV) measurements of single InGaP cells produced approximately 60 muW output power under indoor lighting and 13 mW when exposed to direct sunlight. The power output at 45 deg incident was reduced to 75% of the original. A quad array of InGaP devices produced 57 mW under 1-sun intensity. These devices and the packaging of arrays are used as a proxy for BV components and system designs that would share the same process steps for BV-array fabrication.