Quantitative optical measurement of chemical potentials in intermediate band solar cells

• Published in: Journal of photonics for energy Vol. 5; no. 1; p. 053092
• Main Authors: Rale, Pierre, Delamarre, Amaury, El-Hajje, Gilbert, Tamaki, Ryo, Watanabe, Kentaroh, Shoji, Yasushi, Okada, Yoshitaka, Sugiyama, Masakazu, Lombez, Laurent, Guillemoles, Jean-François
• Format: Journal Article
• Language: English
• Published: Society of Photo-Optical Instrumentation Engineers 05.06.2015; Society of Photo-optical Instrumentation Engineers (SPIE)
• Subjects: Engineering Sciences; Optics; Photonic; quantum dots; photoluminescence; multiquantum wells; intermediate band solar cells; characterization; photovoltaics
• ISSN: 1947-7988; 1947-7988
• DOI: 10.1117/1.JPE.5.053092

Having shown some demonstration of two photon absorption and multiband emission processes in quantum dots (QD), multiquantum wells (MQW), and highly mismatched alloys, intermediate band solar cells are currently the subject of numerous studies. To better understand the underlying mechanisms, our objective is to experimentally probe the multiband operation of this device. We used photoluminescence recorded with a calibrated hyperspectral imager which provides spectrally resolved images with a spatial resolution of 2  μm and spectral resolution of 2 nm on proof of concept QD and MQW solar cells samples. Device emission can be described with the generalized Planck's law from which the quasi-Fermi level splitting of the three bands can be determined. The advantage of the technique is that it can be used to investigate the intermediate band material without the need to make contacts or a full device structure. We also discuss the usefulness of a dual-beam method.