Hybrid Cd‐free CIGS solar cell/TEG device with ZnO nanowires

A green energy device with a CuInGaSe₂ (CIGS) photovoltaic (PV) cell covered with a passive light‐trapping structure (ZnO nanowires (NWs)) and connected to an active energy‐harvesting device (thermoelectric generator (TEG)) is presented. The efficiency of the ZnO NWs/CIGS PV device obtained using a deposition temperature of 550 °C and Cd‐free processes reaches 16.5%. The series‐connected CIGS PV cell with a TEG had a record‐high efficiency of 22% at a cool‐side temperature (T_c) below 5 °C. The open‐circuit voltage (V_oc) of the hybrid CIGS PV/TEG device was increased from 0.64 to 0.85 V. This technology has potential for high‐efficiency energy‐harvesting applications. Copyright © 2014 John Wiley & Sons, Ltd.