Application of high mobility transparent conductors to enhance long wavelength transparency of the intermediate solar cell in multi-junction solar cells

High mobility transparent conducting oxide (HMTCO) materials (mobility > 60 cm2 V− 1 s− 1) have a high transmission over the visible to near infra red wavelength region with resistivity < 2 × 10− 4 Ω cm. We investigate the application of HMTCO materials as transparent contacts for multi-junction and bifacial solar cells to increase the device NIR transmission. Using the HMTCO materials as front contacts significantly reduces absorption and reflection losses of the solar cells, from 850–1500 nm. The need to develop a low temperature process to prepare HMTCO materials as back contacts in semi-transparent solar cells is also emphasized.