Dynamic radiative properties of the Cu(In,Ga)Se2 layer during the co-evaporation process
2010 (English)In: Progress in Photovoltaics, ISSN 1062-7995, E-ISSN 1099-159X, Vol. 18, no 5, 321-327 p.Article in journal (Refereed) Published
A study of the wavelength-integrated emissivity has been performed on the optical stack CuxSe/Cu(In,Ga)Se2/Mo. Thewavelength interval used in the study was 2–20 µm, which covers 95% of the radiated heat from a black body heated to500°C. Substrate temperatures around 500°C are commonly used in production of Cu(In,Ga)Se2 thin films for solar cells.The integrated emissivity was obtained from directional reflectivity measurements of experimental samples with differentthicknesses of the CuxSe layers. It was subsequently compared to the emissivity from numerical simulations based onnewly obtained values of the refractive index values for Cu(In,Ga)Se2 and Cu x Se at these wavelengths. Good agreementwas found between the measured and simulated values. At a Cu(In,Ga)Se2 thickness of 1.8 µm and a Mo thickness of 400 nm, a maximum in the integrated emissivity was found for a CuxSe thickness of 30 nm. The results are valuable inputinto understanding the dynamics of the change in emissivity between Cu-rich Cu(In,Ga)Se2 with segregated CuxSe and Cu-poor single phase Cu(In,Ga)Se2 at temperatures around 500°C. In co-evaporation of Cu(In,Ga)Se2, this emissivity changeis often monitored and used as a process control (end-point detection).
Place, publisher, year, edition, pages
Wiley , 2010. Vol. 18, no 5, 321-327 p.
CIGS, CuxSe, emissivity, segregated layer, co-evaporation, modeling
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject Engineering Science with specialization in Electronics
IdentifiersURN: urn:nbn:se:uu:diva-125722DOI: 10.1002/pip.931ISI: 000280004100002OAI: oai:DiVA.org:uu-125722DiVA: diva2:320777