UC Merced

Lithographically Patterned NW Electrodeposition (LPNE) is a new technique for preparing NWs that was developed by Prof. Erik Menke while he was doing his research in Penner group in 2006. Here, we discuss some of the common problems in state of the art solar cell technology and how we can effectively use LPNE to make next generation Core/Shell NW based solar cells and NIR photodetectors. The first step in the process is the synthesis of Au/PbSe and Au/copper indium diselenide (CIS) core/shell NWs using LPNE. The NWs were synthesized by the aqueous electrodeposition of either PbSe or CIS onto gold NWs prepared by LPNE. The resulting NWs are nanocrystalline, exhibit a sharp boundary between the gold core and the semiconducting coating, and are photoconductive, with enhanced light absorption in smaller NWs which could be due to the cavity effect of the semiconductor shell NWs. The second step is the synthesis of Au/CIS/CdS core/shell/shell based p-n heterojunction NW based solar cells by electrodepositing CdS on top of Au/CIS core/shell NWs. Core/Shell NW based devices prepared by above method are cheap and can be fabricated on cheap substrates like plastics or glass. This technique also gives us the control over size, shape and orientation of the NWs. The beauty of this method is that it gives us a platform to understand some of the basic device physics problems by characterizing each single NW electrically or optically.