Carbon nanotube reinforced cu metal matrix composites for current collection from space photovoltaics

Abstract

There is a strong desire to reduce the weight and increase the power output of photovoltaics devices for space applications while simultaneously reducing cost. The inverted metamorphic multijunction (IMM) cell is an advanced III–V device architecture that provides routes to higher on-orbit power production. A higher specific power is provided by a combination of high efficiency and a thin, low-weight device. As crystalline devices become thinner, however, they are more prone to fracture/cleaving failure. In the most benign case, fracture may simply disconnect a portion of the cell from the power providing circuit. More seriously, fracture can also lead to an open string. These problems may be mitigated by the development of fracture/cleave-tolerant devices. In this paper we consider a novel fabrication route to form metal matrix composites (MMCs) comprised of carbon nanotubes embedded in metals such as Ag and Cu. The MMCs will be used to fabricate grid-lines and back-metal layers for IMM cells with a goal of maintaining cell active area even after fracture/cleavage failures.