InGaN light emitting solar cells with a roughened N-face GaN surface through a laser decomposition process

InGaN-based light-emitting solar cell (LESC) structure with an inverted pyramidal structure at GaN/sapphire interface was fabricated through a laser decomposition process and a wet crystallographic etching process. The highest light output power of the laser-treated LESC structure, with a 56% backside roughened-area ratio, had a 75% enhancement compared to the conventional device at a 20 mA operating current. By increasing the backside roughened area, the cutoff wavelength of the transmittance spectra and the wavelength of the peak photovoltaic efficiency had a redshift phenomenon that could be caused by increasing the light absorption at InGaN active layer. (C) 2010 Optical Society of America