Pixelated GaSb solar cells on silicon by membrane bonding

摘要

We demonstrate thin-film GaSb solar cells which are isolated from a GaSb substrate and transferred to a Si substrate. We epitaxially grow similar to 3.3 mu m thick GaSb P on N diode structures on a GaSb substrate. Upon patterning in 2D arrays of pixels, the GaSb films are released via epitaxial lift-off and they are transferred to Si substrates. Encapsulation of each pixel preserves the structural integrity of the GaSb film during lift-off. Using this technique, we consistently transfer similar to 4 x 4 mm(2) array of pixelated GaSb membranes to a Si substrate with a similar to 80%-100% yield. The area of individual pixels ranges from similar to 90 x 90 mu m(2) to similar to 340 x 340 mu m(2). Further processing to fabricate photovoltaic devices is performed after the transfer. GaSb solar cells with lateral sizes of similar to 340 x 340 mu m(2) under illumination exhibit efficiencies of which compares favorably with extracted values for large-area (i.e., 5 x 5 mm(2)) homoepitaxial GaSb solar cells on GaSb substrates. Published by AIP Publishing.