scholarly journals Influence of Different Types of Recombination Active Defects on the Integral Electrical Properties of Multicrystalline Silicon Solar Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dominik Lausch ◽  
Christian Hagendorf

In this contribution the influence of different types of recombination-active defects on the integral electrical properties of multicrystalline Si solar cells is investigated. Based on a previous classification scheme related to the luminescence behavior of crystal defects, Type-A and Type-B defects are locally distinguished. It is shown that Type-A defects, correlated to iron contaminations, are dominating the efficiency by more than 20% relative through their impact on the short circuit current ISC and open circuit voltage VOC in standard Si material (only limited by recombination active crystal defects). Contrarily, Type-B defects show low influence on the efficiency of 3% relative. The impact of the detrimental Type-A defects on the electrical parameters is studied as a function of the block height. A clear correlation between the area fraction of Type-A defects and both the global Isc and the prebreakdown behavior (reverse current) in voltage regime-2 (−11 V) is observed. An outlier having an increased full-area recombination activity is traced back to dense inter- and intragrain nucleation of Fe precipitates. Based on these results it is concluded that Type-A defects are the most detrimental defects in Si solar cells (having efficiencies > 15%) and have to be prevented by optimized Si material quality and solar cell process conditions.

2009 ◽  
Vol 156-158 ◽  
pp. 357-362 ◽  
Author(s):  
Emanuele Cornagliotti ◽  
Harold F.W. Dekkers ◽  
Caterina Prastani ◽  
Joachim John ◽  
Emmanuel Van Kerschaver ◽  
...  

In this work the impact of hydrogenation from hydrogen-rich amorphous silicon nitride (a-SiNx:H) on dislocations and grain boundaries in multi-crystalline silicon (mc-Si) solar cells is presented. Layers are deposited by means of plasma enhanced chemical vapor deposition (PECVD). Electrical bulk passivation is provided during thermal annealing, in which hydrogen diffuses from a-SiNx:H. The passivation effect is discussed in terms of recombination centers and non-recombinative charge traps reduction as well as in terms of local short circuit current improvement in specially manufactured solar cells.


2019 ◽  
Author(s):  
Mohd Taukeer Khan ◽  
Manuel Salado ◽  
Abdullah R. D. Almohammedi ◽  
Samrana Kazim ◽  
Shahzada Ahmad

<p>The electron and hole selective contact (SC) play a pivotal role in the performance of perovskite solar cells. In order to separate the interfacial phenomenon from bulk, the influence of charge SC was elucidated, by means of impedance spectroscopy. The specific role played by TiO<sub>2</sub> and <i>Spiro-OMeTAD</i> as electron and hole SC in perovskite solar cells was investigated at short circuit condition at different temperatures. We have probed MAPbI<sub>3</sub> and (FAPbI<sub>3</sub>)<sub>0.85</sub>(MAPbBr<sub>3</sub>)<sub>0.15 </sub>and elucidated parameters such as charge carrier mobility, recombination resistance, time constant and charge carrier kinetics in perovskite layer and at the interface of perovskite/SC. Charge carrier mobility in mixed perovskite was found to be nearly two order of magnitude higher as compared to MAPbI<sub>3</sub>. Moreover, the carrier mobility in devices with only electron SC was found to be higher as compared only hole SC. The charge accumulation at TiO<sub>2</sub>/perovskite/<i>Spiro</i>-OMeTAD interfaces were studied via frequency dependent capacitance, revealing higher charge accumulation at perovskite/S<i>piro</i>-OMeTAD than at TiO<sub>2</sub>/perovskite interface. By performing varying temperature frequency dependent capacitance measurements the distribution of density of state within the bandgap of the perovskites, the emission rate of electrons from the trap states and traps activation energy was determined. </p>


2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
E. Gaubas ◽  
T. Ceponis ◽  
V. Kalendra ◽  
J. Kusakovskij ◽  
A. Uleckas

Technique for barrier evaluation by measurements of current transients induced by linearly increasing voltage pulse based on analysis of barrier and diffusion capacitance changes is presented. The components of the barrier capacitance charging and generation/recombination currents are discussed. Different situations of the impact of deep center defects on barrier and diffusion capacitance changes are analyzed. Basics of the profiling of layered junction structures using the presented technique are discussed. Instrumentation for implementation of this technique and for investigations of the steady-state bias infra-red illumination and temperature dependent variations of the barrier capacitance charging and generation/recombination currents are described. Applications of this technique for the analysis of barrier quality in solar cells and particle detectors fabricated on silicon material are demonstrated.


2015 ◽  
Vol 6 (1) ◽  
pp. 15-20 ◽  
Author(s):  
M Mohiuddin ◽  
MB Latif

This study was conducted to determine the contamination of E. coli and Salmonella for different types of foods in Chittagong city area. In case of laboratory examination, almost half (49.58%) of the samples were contaminated where 28.75% positive for E. coli. and 20.83% for Salmonella. The positive cases for type A sample was 20 out of 96 constituting 20.83% whereas the positive cases for type B sample was 49 out of 144 constituting 34.03% for E. coli. The positive cases of type A sample was 15 out of 96 making up 15.63% and for type B sample was 35 out of 144 making up 24.31% for Salmonella.A chi-square (?2) test was used to examine the equality of observed proportions for E. coli and Salmonella of each item of both types of food where significant difference among the observed proportion for E. coli (p-value<0.01) and Salmonella (p-value=0.032) for different items of A type and for E. coli (p-value<0.01) for different items of B type were observed and an odds ratio (OR) was measured for association between exposure and outcome where the probability of contaminated by E. coli of type B food is higher than contaminated of type A food (OR= 1.96 and CI:1.07-3.58). The probability of contaminated by Salmonella of type B food was higher than type A food (OR= 1.73 and CI: 0.89-3.39).The comparatively high bacteria in type B samples indicated contamination from water, practice of inadequate hygienic measures, mishandling, improper storage, inadequate cooking and above all unhygienic condition of the retail shops.DOI: http://dx.doi.org/10.3329/jesnr.v6i1.22034 J. Environ. Sci. & Natural Resources, 6(1): 15-20 2013


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3397 ◽  
Author(s):  
Jong Lim ◽  
Woo Shin ◽  
Hyemi Hwang ◽  
Young-Chul Ju ◽  
Suk Ko ◽  
...  

Cut solar cells have received considerable attention recently as they can reduce electrical output degradation when the c-Si solar cells (crystalline-silicon solar cells) are shaded. Cut c-Si solar cells have a lower short-circuit current than normal solar cells and the decrease in short-circuit currents is similar to the shading effect of c-Si solar cells. However, the results of this study’s experiment show that the shadow effect of a c-Si solar cell reduces the V o c (open circuit voltage) in the c-Si solar cell but the V o c does not change when the c-Si solar cell is cut because the amount of incident light does not change. In this paper, the limitations of the electrical power analysis of the cut solar cells were identified when only photo current was considered and the analysis of the electric output of the cut c-Si solar cells was interpreted with a method different from that used in previous analyses. Electrical output was measured when the shaded and cut rates of c-Si solar cells were increased from 0% to 25, 50 and 75%, and a new theoretical model was compared with the experimental results using MATLAB.


2002 ◽  
Vol 16 (01n02) ◽  
pp. 57-63 ◽  
Author(s):  
X. DENG ◽  
W. WANG ◽  
S. HAN ◽  
H. POVOLNY ◽  
W. DU ◽  
...  

This paper reports the impact of a wide bandgap p-type hydrogenated nanocrystalline silicon (nc-Si:H) on the performances of hydrogenated amorphous silicon (a-Si:H) based solar cells. The p-layer consists of nanometer-sized Si Crystallites and has a wide effective bandgap determined mainly by the quantum size-confinement effect (QSE). By incorporation of this p-layer into the devices we have obtained high performances of a-Si:H top solar cells with V oc = 1.045 V and FF = 70.3%, and much improved mid and bottom a-SiGe:H cells, deposited on stainless steel (SS) substrate. The effects of the band-edge mismatch at the p/i-interface on the I-V characteristics of the solar cells are discussed on the bases on the bases of the density-functional approach and the AMPS model.


2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Kuen-Hsien Wu ◽  
Chia-Chun Tang

Trenched electrodes were proposed to enhance the short-circuit current and conversion efficiency of polycrystalline-silicon (poly-Si) solar cells with nanoporous silicon (NPS) surface layers. NPS films that served as textured surface layers were firstly prepared on heavily doped p+-type (100) poly-Si wafers by anodic etching process. Interdigitated trenches were formed in the NPS layers by a reactive-ion-etch (RIE) process and Cr/Al double-layered metal was then deposited to fill the trenches and construct trenched-electrode-contacts (TEC’s). Cells with TEC structures (called “TEC cells”) obtained 5.5 times higher short-circuit current than that of cells with planar electrode contacts (called “non-TEC cells”). Most significantly, a TEC cell achieved 8 times higher conversion efficiency than that of a non-TEC cell. The enhanced short-circuit current and conversion efficiency in TEC cells were ascribed to the reduced overall series resistance of devices. In a TEC cell, trenched electrodes provided photocurrent flowing routes that directly access the poly-Si substrates without passing through the high resistive NPS layers. Therefore, the application of NPS surface layers with trenched electrodes is a novel approach to development of highly efficient poly-Si solar cells.


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