scholarly journals Ultrathin Oxide Passivation Layer by Rapid Thermal Oxidation for the Silicon Heterojunction Solar Cell Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Youngseok Lee ◽  
Woongkyo Oh ◽  
Vinh Ai Dao ◽  
Shahzada Qamar Hussain ◽  
Junsin Yi

It is difficult to deposit extremely thin a-Si:H layer in heterojunction with intrinsic thin layer (HIT) solar cell due to thermal damage and tough process control. This study aims to understand oxide passivation mechanism of silicon surface using rapid thermal oxidation (RTO) process by examining surface effective lifetime and surface recombination velocity. The presence of thin insulating a-Si:H layer is the key to get highVocby lowering the leakage current (I0) which improves the efficiency of HIT solar cell. The ultrathin thermal passivation silicon oxide (SiO2) layer was deposited by RTO system in the temperature range 500–950°C for 2 to 6 minutes. The thickness of the silicon oxide layer was affected by RTO annealing temperature and treatment time. The best value of surface recombination velocity was recorded for the sample treated at a temperature of 850°C for 6 minutes at O2flow rate of 3 Lpm. A surface recombination velocity below 25 cm/s was obtained for the silicon oxide layer of 4 nm thickness. This ultrathin SiO2layer was employed for the fabrication of HIT solar cell structure instead of a-Si:H, (i) layer and the passivation and tunneling effects of the silicon oxide layer were exploited. The photocurrent was decreased with the increase of illumination intensity and SiO2thickness.

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Myeong Sang Jeong ◽  
Yonghwan Lee ◽  
Ka-Hyun Kim ◽  
Sungjin Choi ◽  
Min Gu Kang ◽  
...  

In the fabrication of crystalline silicon solar cells, the contact properties between the front metal electrode and silicon are one of the most important parameters for achieving high-efficiency, as it is an integral element in the formation of solar cell electrodes. This entails an increase in the surface recombination velocity and a drop in the open-circuit voltage of the solar cell; hence, controlling the recombination velocity at the metal-silicon interface becomes a critical factor in the process. In this study, the distribution of Ag crystallites formed on the silicon-metal interface, the surface recombination velocity in the silicon-metal interface and the resulting changes in the performance of the Passivated Emitter and Rear Contact (PERC) solar cells were analyzed by controlling the firing temperature. The Ag crystallite distribution gradually increased corresponding to a firing temperature increase from 850 ∘C to 950 ∘C. The surface recombination velocity at the silicon-metal interface increased from 353 to 599 cm/s and the open-circuit voltage of the PERC solar cell decreased from 659.7 to 647 mV. Technology Computer-Aided Design (TCAD) simulation was used for detailed analysis on the effect of the surface recombination velocity at the silicon-metal interface on the PERC solar cell performance. Simulations showed that the increase in the distribution of Ag crystallites and surface recombination velocity at the silicon-metal interface played an important role in the decrease of open-circuit voltage of the PERC solar cell at temperatures of 850–900 ∘C, whereas the damage caused by the emitter over fire was determined as the main cause of the voltage drop at 950 ∘C. These results are expected to serve as a steppingstone for further research on improvement in the silicon-metal interface properties of silicon-based solar cells and investigation on high-efficiency solar cells.


1995 ◽  
Vol 386 ◽  
Author(s):  
A. Kaniava ◽  
U. Menczigar ◽  
J. Vanhellemont ◽  
J. Poortmans ◽  
A. L. P. Rotondaro ◽  
...  

ABSTRACTThe carrier recombination rate in high-quality FZ and Cz silicon substrates is studied by contactless infrared and microwave absorption techniques. Different surface treatments covering a wide range of surface recombination velocity have been used for the separation of bulk and surface recombination components and evaluating of the efficiency of passivation. Limitations of effective lifetime approach are analyzed specific for low and high injection level. Sensitivity limits of the techniques for iron contamination are discussed


2018 ◽  
Vol 09 (02) ◽  
pp. 189-201
Author(s):  
Ousmane Diasse ◽  
Amadou Diao ◽  
Mamadou Wade ◽  
Marcel Sitor Diouf ◽  
Ibrahima Diatta ◽  
...  

2021 ◽  
Author(s):  
Z. Pezeshki ◽  
A. Zekry

The book presents a comprehensive survey about advanced solar cell technologies. Focus is placed on semiconductor materials, solar cell efficiency, improvements in surface recombination velocity, charge density, high ultraviolet (UV) sensitivity, modeling of solar cells etc. The book references 281 original resources with their direct web links for in-depth reading.


1997 ◽  
Vol 477 ◽  
Author(s):  
Y. Ogita ◽  
Y. Uematsu ◽  
H. Daio

ABSTRACTBi-surface photoconductivity decay (BSPCD) method has been useful to obtain the true bulk lifetime and surface recombination velocities in silicon wafers with variously finished surfaces. Thermally oxidized n-type CZ silicon wafers with and without a poly-Si back seal (PBS) were characterized with the BSPCD method using 500 MHz-UHF wave reflection. It has been found that the surface recombination velocity of the PBS surface is, 4027 cm/s while that of the no-PBS surface is 16 cm/s, for example. The very fast surface recombination velocity is attributed to the poly-Si / Si interface character. Moreover, the bulk lifetime calculated in the PBS wafer is much higher than that in the no-PBS one, which reveals the PBS gettering performance for the thermal oxidation induced contamination.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4986
Author(s):  
Gokul Sidarth Thirunavukkarasu ◽  
Mehdi Seyedmahmoudian ◽  
Jaideep Chandran ◽  
Alex Stojcevski ◽  
Maruthamuthu Subramanian ◽  
...  

Expeditious urbanization and rapid industrialization have significantly influenced the rise of energy demand globally in the past two decades. Solar energy is considered a vital energy source that addresses this demand in a cost-effective and environmentally friendly manner. Improving solar cell efficiency is considered a prerequisite to reinforcing silicon solar cells’ growth in the energy market. In this study, the influence of various parameters like the thickness of the absorber or wafer, doping concentration, bulk resistivity, lifetime, and doping levels of the emitter and back surface field, along with the surface recombination velocity (front and back) on solar cell efficiency was investigated using PC1D simulation software. Inferences from the results indicated that the bulk resistivity of 1 Ω·cm; bulk lifetime of 2 ms; emitter (n+) doping concentration of 1×1020 cm−3 and shallow back surface field doping concentration of 1×1018 cm−3; surface recombination velocity maintained in the range of 102 and 103 cm/s obtained a solar cell efficiency of 19%. The Simulation study presented in this article allows faster, simpler, and easier impact analysis of the design considerations on the Si solar cell wafer fabrications with increased performance.


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