A ceramic target with Ga:In:Sn=4:64:32 metal ratio has been sintered and used for RF sputtering process to develop high quality Ga doped ITO (GITO) transparent conductive oxide layers, particularly for photovoltaic applications. The sputtering parameters (sputtering power, oxygen flow, and substrate temperature) have been varied first and optimized with respect to the resistivity measurements. The layers deposited under optimized conditions were then post-annealed at different temperatures (200−500 ⁰C) either in the air or in nitrogen atmosphere in order to further improve the conductivity. The deposited 200 nm thick GITO layer has high electron mobility (50 cm2/Vs) at relatively low resistivity (0.90 mΩcm) although the free electron concentration is kept low (1,4e20 cm-3) to prevent excessive free-carrier absorption. Thus, high transmission of the layer (~80% at 400−1500 nm) is obtained.
COBISS.SI-ID: 29163815
In the first part a review of methods and simulators in the field of optical modeling and simulations of thin-film solar cells is given. We introdiuce an idea of a coupled modeling approach. We show simulation results of rigorous optical simulations of Si solar cells including nanotextures, employing a model of realistic layer growth. Furthermore, simulations of organic solar cells including macrotextures were carried out with simulator CROWM.
COBISS.SI-ID: 10835540
UV nanoimprint lithography (UV NIL) is a novel effective approach of introducing the desired textures into the solar cell structures. Compared to the other techniques of texturization it is simple, cost-effective and fast. As the UV NIL lacquers are non-conductive, an additional conductive layer of transparent conductive oxide (TCO) has to be deposited on top of the UV NIL layer to form electrical contact. In our case, a gallium doped ITO (GITO) was used as a TCO. In this paper, the processes of sample preparation are presented. The successfulness of the deposition is determined by sheet resistance, optical (transmission) and surface morphology measurements, which were used to establish the suitability of the process, texture transfer fidelity and conformal growth of the GITO layer.
COBISS.SI-ID: 11126868