Selective emitter formation via single step doping through laser patterned mask oxide layer for monocrystalline silicon solar cells

Çiftpınar, Emine Hande
Selective emitter is one of the new approaches for higher efficiency solar cells. Although selective emitter cells could be processed by several different methods such as; etch back process, laser doping, ion implantation, doping paste, a different method based on diffusion through a laser patterned oxide layer was studied in this thesis. Utilization of pattern oxide layer as a diffusion barrier enables to obtain selective emitter profile via single step doping which reduces overall production cost and time significantly. In this work, selective emitter solar cells were fabricated via single step doping through a laser patterned oxide. Oxide thickness, doping recipe, laser parameters and wet cleaning steps were optimized to reach the sheet resistance values needed for an efficient cell design. In addition, surface passivation studies were also conducted to further improve cell performance. A low temperature, dry oxidation step was also added to process sequence. Then, monocrystalline-Si selective emitter and reference solar cells were fabricated. Both electrical and optical characterizations including reflection, lifetime, external quantum efficiency, Suns-Voc and current-voltage measurements were systematically carried out. It was observed that cells based on that new selective emitter structure could be used to reach higher conversion efficiency values compared to standard cell design with a proper finger design


Contact resistivity analysis of different passivation layers via transmission line method measurements
Kökbudak, Gamze; Turan, Raşit; Yerci, Selçuk; Department of Micro and Nanotechnology (2017)
Crystalline silicon (c-Si) homojunction solar cells constitute over 90% of the current photovoltaic market. Although the standard solar cells are cost effective and easy to process, their efficiency potential is unfortunately limited. Currently, more innovative cell concepts appeared with their high efficiency potential coupled with low costs. Since the recombination at surfaces and under metal contacts is one of the major obstacles against high conversion efficiencies, surface passivation has primary impor...
Nanostructure enhanced photovoltaic devices
Aurang, Pantea; Ünalan, Hüsnü Emrah; Turan, Raşit; Department of Micro and Nanotechnology (2015)
There are mainly three generations of solar cells that have been categorized by considering their efficiency and manufacturing cost. Although lots of investigations and research is going on in this field, but the first generation solar cells are most commercially available solar cells. First generation solar cells consist of single and multi-crystalline silicon (Si), which has been doped typically by phosphorus and boron in a p-n junction configuration. Si is non-toxic, relatively low cost and naturally abu...
Surface texturing study with aluminum induced texturing method on soda-lime glass substrates for thin film solar cells
Ünal, Mustafa; Turan, Raşit; Ünalan, Hüsnü Emrah; Department of Micro and Nanotechnology (2017)
It is essential to employ an effective light trapping scheme to decrease the cost of produced solar electricity further in thin film solar cell technologies. There are several methods that can be used for light trapping and aluminum induced texturing (AIT) is one of them. The aim of this thesis study is to obtain highly effective light trapping interface via texturing of glass surface by AIT process. The resultant texture is affected by several parameters such as Al thickness, annealing time and temperature...
Surface modification of multi-crystalline silicon in photovoltaic cell by laser texturing
Radfar, Behrad; Turan, Raşit; Yerci, Selçuk; Department of Micro and Nanotechnology (2019)
Surface of crystalline silicon solar cell plays an important role in its performance. It affects the optical properties which can be determined by surface’ reflectance. To minimize the reflection from the flat surface, thus, improve light trapping, the crystalline silicon wafers must be textured. Through the texturing process, roughness is introduced at the surface, so the incident light has a larger probability of being absorbed into the solar cell. Monocrystalline silicon solar cells can typically be text...
Simulation Studies of Hole Textured and Planar Microcrystalline Silicon Solar Cell at Different Zenith Angle
Zainab, Sana; Hussain, Shahzad; Altinoluk, Serra H.; Turan, Raşit (2017-09-23)
Efficiency of solar cell greatly depends on its interaction with input solar irradiance. For highly efficient solar cell, absorption of input light should be maximum at all angles. Different surface texturing techniques like pyramid texturing, cone texturing, pillar texturing have been used to increase absorption of light in solar cell. Micro-hole Surface texturing is getting popular in absorption of solar radiation at higher zenith angle. In this paper, effect of varying zenith angle on hole textured solar...
Citation Formats
E. H. Çiftpınar, “Selective emitter formation via single step doping through laser patterned mask oxide layer for monocrystalline silicon solar cells,” M.S. - Master of Science, Middle East Technical University, 2014.