22 September 2010 Room temperature transport measurements on Bridgman-grown CuInSe2 with added sodium
Author Affiliations +
Proceedings Volume 7750, Photonics North 2010; 775030 (2010) https://doi.org/10.1117/12.869576
Event: Photonics North 2010, 2010, Niagara Falls, Canada
Thermoelectric power, Hall coefficient and resistivity measurements were carried out on material cut from monocrystalline ingots of CuInSe2. The ingots were grown using a vertical-Bridgman procedure, whereby Cu, In and Se were melted and directionally cooled within a sealed quartz ampoule. When stoichiometric proportions of the starting elements were used, the material was always p-type, with hole concentrations of the order of 1017-1018 cm-3. However, the incorporation of a sufficient amount of sodium (0.3 at. %) into the melt was seen to result in n-type material, with electron concentrations of the order of 1016. This conversion from p to n was hindered by the inclusion Se above stoichiometry into the ampoule, and more Na was required for the material to change type. The mobility of the p-type samples, with low sodium additions (0-0.2 at. %), was on average 17 cm2V-1s-1, and was seen to be higher for material grown from melts containing excess Se, corresponding to the chemical formula CuInSe2.2, than from stoichiometry. SEM/EDX (Scanning electron microscope / Energy-dispersive X-ray spectroscopy) analysis of the ingots after growth indicated no sodium residing within the interior of the bulk material, but a significant amount was found on the exterior surface in the case of an ingot grown with CuInSe2.05 and 5 at. % Na. Various deposits found within the ampoules after growth were analyzed, including a copper-rich precipitate found only in ampoules which included a high concentration of Na and a low concentration of excess Se, resulting in n-type material.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
H. F Myers, C. H. Champness, I. Shih, "Room temperature transport measurements on Bridgman-grown CuInSe2 with added sodium", Proc. SPIE 7750, Photonics North 2010, 775030 (22 September 2010); doi: 10.1117/12.869576; https://doi.org/10.1117/12.869576


Back to Top