Electrochemical synthesis of CdSe/CdTe nanowires for hybrid photovoltaic structures

ABSTRACTAdvanced electrochemical technique was elaborated to fabricate self-organized CdSe nanowire structures from aqueous electrolytes on ITO coated glass substrates. We have recently been demonstrated successful electrochemical formation of free-assistent CdSe nanowire structures with diameter around 30 nm. This work has extended our previous research of electrodeposition of Cd chalcogenide (CdSe, CdS) nanowires to formation of core-shell CdSe/CdTe photosensitive nanowire structures. CdSe nanowire structures were synthesized potentiostatically from an acidic solution of H2SeO3 and CdCl2 at room temperature. Then the CdSe (core) nanowires were further passivated with CdTe (shell) thin film by method of electrochemical deposition from acidic solution of H2TeO3 and CdCl2. The effect of interfacial passivation with CdTe layer on the performance of the prepared photovoltaic structures was investigated and special account was paid to the morphology, composition and photovoltaic properties of obtained CdSe/CdTe nano-layers. It should be noted, that electrically conductive polymer photoabsorbers (poly (3-octylthiophene) etc.) were applied successfully for preparation of high work-function ohmic contact-sensitizer layer to CdTe shells. The electrodeposition and spin-casting techniques were applied step-by-step to prepare complete hybrid photovoltaic structures.