Papers by Author: A. Öpik

Abstract: Thin films of Cu-In-Se (CISe) photoabsorber with overall composition of CuIn3Se5 were deposited onto glass/ITO substrates by using physical vapour deposition (PVD) technique. Thermal conditions for the substrates during deposition process and following thermal annealing were selected with the purpose to prepare polycrystalline n-CuIn3Se5 photoabsorber layers for the hybrid photovoltaic structures based on inorganic photoabsorber and conductive polymer functional layers. It was found, that the CISe layers deposited at the temperature of substrate of 200 °C and annealed at the temperature range of 450-500 oC in vacuum and double annealed in argon and vacuum at 500 oC demonstrate high photosensitivity and photoconductivity under white light illumination of 100 mW/cm2 intensity. Obtained results show the chalcopyrite structure of prepared photoabsorber films with good adhesion to the glass/ITO substrate.

Abstract: This paper reviews results of studies on different materials and technologies for polycrystalline solar cells conducted at Tallinn University of Technology. Structural properties and defect structure of kesterite CZTS compounds (Cu2ZnSnSe4, Cu2ZnSn(SSe)4) were studied. Influence of selenization parameters of a Zn-Cu-Sn stacked layer on the CZTS layer growth and on the morphology, distribution of elements was analyzed. All the results obtained have been used to optimize the technology of producing solar cell structures in different designs. Cu2ZnSnSe4 and, Cu2ZnSn(SSe)4 based monograin layer solar cells were developed.