Development of ZnTe1−xOx intermediate band solar cells

• Main Authors: Tanaka, T, Kin Man Yu, Stone, P, Beeman, J W, Dubon, O, Reichertz, L A, Kao, V M, Nishio, M, Walukiewicz, W
• Format: Conference Proceeding
• Language: English
• Subjects: Junctions; Lighting; Materials; Photovoltaic cells; Photovoltaic systems; Sun
• ISSN: 0160-8371
• DOI: 10.1109/PVSC.2010.5614215

We describe the fabrication of ZnTe 1-x O x intermediate band solar cell (IBSC) using the combination of oxygen ion implantation and pulsed laser melting. Also, we report the first demonstration of homojunction ZnTe solar cells in which n-ZnTe layer is fabricated by thermal diffusion of Al into p-ZnTe. The preliminary results of the ZnTe 1-x O x IBSC are compared with the ZnTe cell. The homojunction ZnTe solar cells exhibited photovoltaic activity with an open circuit voltage of approximately 0.9 V and a maximum short circuit current (J SC ) of 1.75 mA/cm 2 . J SC was found to depend strongly on the location of pn-junction, with shallower pn-junction depth, corresponding to higher J SC . Photo-modulated reflectance spectra of ZnTe 1-x O x , show two optical transitions from the valence band to the conduction subband E + (~2.5 eV) and from the valence band to the intermediate band E - (~1.7 eV). The external quantum efficiency of ZnTe 1-x O x solar cell clearly shows PV responses due to the transition from valence band to the two conduction subbands (E - and E + ) demonstrating the photovoltaic action through the intermediate band in this highly mismatched alloy.