Due to the extreme sensitivity of the partial elemental currents (i.e.,iCd, iTe) and, hence, stoichiometry to deposition voltage, temperature, mass transport, and ambient light intensity during electrodeposition of semiconductor films, it is important to implement in-situ methods for monitoring the stoichiometry and related semiconductor efficacy of the growing film. We report investigation of open circuit rest potential (Eoc) voltammetry as one such method during electrodeposition of CdTe from aprotic electrolytes such as ethylene glycol. Plots of transient open circuit potential versus sweep voltage exhibit distinct transition and plateau structures corresponding to Te, CdTe, and Cd phases and correlating with the appearance/disappearance of photocurrent, x-ray diffraction evidence of the three phases, and optical obsorption spectroscopy. In particular, the Eoc plateau corresponding to deposition of near-stoichiometric CdTe can be used to monitor and control the deposition process.
Kemp, Brandon; Engelken, Robert; Raza, Arif; Siddiqui, Arees; and Mustafa, Omer
"Diagnostics of CdTe Electrodeposition by Rest Potential Voltammetry,"
Journal of the Arkansas Academy of Science: Vol. 49
, Article 21.
Available at: http://scholarworks.uark.edu/jaas/vol49/iss1/21