Physical device simulation of dopant-free asymmetric silicon heterojunction solar cell featuring tungsten oxide as a hole-selective layer with ultrathin silicon oxide passivation layer

Mehmood, Haris
Nasser, Hisham
Zaidi, Syed Muhammad Hassan
Tauqeer, Tauseef
Turan, Raşit
The dopant-related issues are amongst the major performance bottleneck in crystalline silicon solar cells that can be alleviated via implementation of dopant-free layers. This work presents the implementation of tungsten oxide (WOx) and titanium oxide (TiOx) as hole- and electron-selective films for heterostructure solar cell design whereby n-type Si wafer has been passivated with ultrathin silicon oxide (SiO2) layer. Several designs have been investigated including passivated hydrogenated amorphous silicon (i-a-Si:H) and characterized by evaluating work function, electron affinity, interfacial charge, and layer thickness. The high work function of WOx induces significant upward band bending to permit holes transportation towards anode, whereas, low electron-affinity for TiOx reduces the barrier against electrons at the cathode. Smaller band offsets have been observed against minority carriers for devices that employ passivated i-a-Si:H film. However, incorporating SiO2 significantly improves the energy barrier height against minority carriers that leads to an enhancement in electric field along with reduction in recombination. The best-performance device with an optimum SiO2 thickness of 1 nm numerically validated V-oc of 751 mV, J(sc) 40.2 mA/cm(2), FF 79.7%, and rl of 24.06%. A comparative analysis with hole-selective vanadium oxide (V2Ox) demonstrated eta of 21.73% limited by the low work function of V2Ox. (C) 2021 Elsevier Ltd. All rights reserved.


Physical Device Simulation of Partial Dopant-Free Asymmetric Silicon Heterostructure Solar Cell (P-DASH) based on Hole-selective Molybdenum Oxide (MoOx) with Crystalline Silicon (cSi)
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Silicon heterostructure solar cell based on p-type amorphous silicon(aSi:H) poses fundamental performance limitations due to the narrower band gap of aSi: H and the presence of band gap defects states. Such p-type a-Si: H layer can be replaced by novel carrier-selective Transition Metal Oxide (TMO) films such as Molybdenum oxide(MoOx) that offers higher work function and reduced parasitic absorption and thus enhanced photovoltaic performance. In this work, Silvaco TCAD simulation of Partial Dopant-Free Asym...
Simulation of an efficient silicon heterostructure solar cell concept featuring molybdenum oxide carrier-selective contact
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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...
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Orhan, Efe; Ünalan, Hüsnü Emrah; Department of Metallurgical and Materials Engineering (2019)
Crystalline silicon (c-Si) solar cells fabricated on p-type wafers are still dominating the photovoltaic (PV) industry due to advantages in device processing and early focus on p-type cells in the development phase of the industry. Over the years, studies on n-type Czochralski (CZ) substrates have shown that they can be more desirable for the terrestrial applications due to superior material and process advantages such as higher minority carrier lifetime, easier passivation of the surface, absence of light ...
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In the development of high efficiency crystalline Si solar cells, decreasing bulk and surface recombination velocities of the minority carriers is vital. As the bulk recombination could be suppressed by enhancing the material quality, the effect of surface recombination on cell performance becomes more dominant. Also, recent studies have revealed that the area under the metal contacted region needs to be passivated to minimize the carrier recombination. The passivation of front and back surface of the cell ...
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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...
Citation Formats
H. Mehmood, H. Nasser, S. M. H. Zaidi, T. Tauqeer, and R. Turan, “Physical device simulation of dopant-free asymmetric silicon heterojunction solar cell featuring tungsten oxide as a hole-selective layer with ultrathin silicon oxide passivation layer,” RENEWABLE ENERGY, vol. 183, pp. 188–201, 2022, Accessed: 00, 2022. [Online]. Available: