Canar, Hasan Hüseyin
PECVD deposited SiNx has been used in PV industry especially for PERC solar cell as anti-reflection coating (ARC) and passivating layer [1]. However, its limited optical and electrical properties create a barrier for achieving higher solar cell efficiencies. For that reason, an alternative is introduced that is SiOxNy thin film with adjustable refractive index can be tuned as low as SiO2 [2]. In this thesis, deposited SiNx and SiOxNy films were characterized by various measurement methods such as SE, FTIR, C-V and PCD. FTIR measurements revealed that H content of the films increases for higher refractive indices. While Qf of the SiNx films becomes higher, Dit reduces significantly for lower indices. SiOxNy film with index of 1.73 has the smallest Dit value which is related to higher Si-O density. Fabricated symmetrical samples showed that depositing few nm of SiOxNy layer beneath the SiNx film improves iVoc values of both n and p-type undoped wafers. Qf of Al2O3/SiNx stack with lower index of SiNx film improved with peak firing temperature. iVoc values resisted to higher peaks which is attributed to lower H content in the SiNx film. Optimized ARC layers were simulated with OPAL 2 for comparing absorption/reflection losses [3]. SiNx with lower index at the interface reduced the absorption of light in the thin film. Also, depositing SiOxNy on top of SiNx film resulted in lower reflection in U-V region compared to single layer SiNx film. In the scope of the simulation results, JGen improved with absolute 0.19 mA.cm-2. According to I-V results of the fabricated PERC solar cells, Jsc values were in the same trend as the simulation results, thus resulting in higher photoconversion efficiency.


Optimization of Silicon Nitride (SiN X ) Anti-reflective coating (arc) and passivation layers using industrial plasma enhanced chemical vapor deposition (pecvd) for perc type solar cells
Kökbudak, Gamze; Orhan, Efe; Es, Fırat; Semiz, Emel; Turan, Raşit (2018-07-06)
This study focuses on optimization of silicon nitride (SiN X ) Anti Reflective Coating (ARC) layer deposited on the front side of industrial Passivated Emitter and Rear Cell (PERC) type solar cells in an industrial tube type plasma enhanced chemical vapor deposition (PECVD) tool. Reflection and thickness optimization studies of ARC layer was carried out through a matrix composed of critical plasma parameters. Characterization of the layers were conducted via ellipsometry and reflectivity measurements for un...
Comparison of crystal Si solar cells fabricated on p-type and n-type float zone silicon wafers
Bilgen, Makbule; Turan, Raşit; Department of Physics (2013)
Solar cells are traditionally fabricated on p-type Si substrates due to the high electron diffusion length in p-type substrate. However, high quality float zone silicon wafers provide higher carrier life time for holes in the n-type substrates, making it possible to fabricate high efficiency solar cells in this type of substrate. Superior properties of n-type substrates have created a tendency towards fabrication of n-type solar cells in photovoltaic market technology considerably. It is even forecasted tha...
Optimization of open-tube furnace diffusion with Bbr3 liquid source for industrial p-type boron doping process
Orhan, Efe; Kökbudak, Gamze; Semiz, Emel; Es, Fırat; Turan, Raşit (Middle East Technical University; 2018-07-06)
In this study, optimization of boron emitter for n-type crystalline Si solar cells has been studied in detail. Industrial open-tube (atmospheric) furnace with BBr3 as liquid B source was utilized which is a preferred dopant for the diffusion process of n-type wafers in industry [1] [2]. During the processes, full boat (270 wafers) n-type square samples were used to investigate the uniformity from gas zone to door zone and inside the wafer. To achieve uniform boron emitters on large n-type substrates, parame...
Application of Si Nanowires Fabricated by Metal-Assisted Etching to Crystalline Si Solar Cells
KULAKCI, Mustafa; ES, FIRAT; ÖZDEMİR, Baris; Ünalan, Hüsnü Emrah; Turan, Raşit (2013-01-01)
Reflection and transmission through a solar cell can be significantly reduced using light-trapping structures. This approach can be applied to both crystalline and thin-film solar cells to improve the light absorption and conversion efficiency of the cell. In this study, vertically aligned Si nanowires were fabricated over a large area via a metal-assisted etching technique. Following a detailed parametric study, nanowires were applied to industrial-size (156 mm x 156 mm) Si solar cells. The reflectivity fr...
Simulation of an efficient silicon heterostructure solar cell concept featuring molybdenum oxide carrier-selective contact
MEHMOOD, Haris; NASSER, Hisham; Tauqeer, Tauseef; HUSSAIN, Shahzad; Ozkol, Engin; Turan, Raşit (2018-03-25)
Transition metal oxides/silicon heterocontact solar cells are the subject of intense research efforts owing to their simpler processing steps and reduced parasitic absorption as compared with the traditional silicon heterostructure counterparts. Recently, molybdenum oxide (MoOx, x<3) has emerged as an integral transition metal oxide for crystalline silicon (cSi)-based solar cell based on carrier-selective contacts (CSCs). In this paper, we physically modelled the CSC-based cSi solar cell featuring MoOx/intr...
Citation Formats
H. H. Canar, “OPTIMIZATION OF SILICON-OXYNITRIDE THIN FILMS FOR CRYSTALLINE SILICON (C-Si) PERC CELL,” M.S. - Master of Science, Middle East Technical University, 2022.