Energy Dependence of Defects in a-Si:H Solar Cells During Degradation and Annealing Processes

1997 ◽  
Vol 467 ◽  
Author(s):  
Domenico Caputo ◽  
Francesco Lemmi ◽  
Fabrizio Palma
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Recovery Rate ◽  
Short Circuit ◽  
Forward Bias ◽  
Short Circuit Current ◽  
Silicon Solar Cells ◽  
Capacitance Measurements ◽  
Current Voltage ◽  
Induced Changes

ABSTRACTIn this work we report on the effect of current-induced degradation and annealing on p-i-n amorphous silicon solar cells. Current-voltage curves and capacitance measurements under forward bias have been used to monitor the current-induced changes as a function of time. We found that the recovery rate increases with the annealing current, while the stabilized value of efficiency decreases. Comparison of short circuit current and capacitance evolution suggests that defect kinetics in the electronic gap occurs in a different way during degradation and annealing. This behavior can be modeled assuming a faster annealing of defects closest to the extended band and a slower annealing of mid-gap defects.

Optical Losses in Amorphous Silicon Solar Cells due to Back Reflectors

1997 ◽  
Vol 467 ◽  
Author(s):  
B. L. Sopori ◽  
J. Madjdpour ◽  
B. Von Roedern ◽  
W. Chen ◽  
S. S. Hegedus
Keyword(s):  
Solar Cells ◽  
Numerical Model ◽  
Amorphous Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Silicon Solar Cells ◽  
Optical Losses ◽  
Back Reflectors ◽  
Current Densities ◽  
Initial Results

ABSTRACTWe have used a new numerical model and here present initial results on how texturing and backreflectors affect the maximum achievable short-circuit current densities in amorphous silicon solar cells.

A Carrier Lifetime Model for the Optical Degradation of Amorphous Silicon Solar Cells

1985 ◽  
Vol 49 ◽  
Author(s):  
Z E. Smith ◽  
S. Wagner
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Carrier Lifetime ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Carrier Lifetimes ◽  
Bond Density ◽  
Degradation Data

AbstractThe light-induced performance degradation of amorphous silicon solar cells is described well by a model in which the carrier lifetimes are determined by the dangling bond density. The kinetics of the defect generation follow the model in which band-to-band recombination provides the energy for the creation of dangling bonds, which in turn introduce gap states that reduce carrier lifetime. Degradation will be slower in solar cells operating at lower excess carrier concentrations. This is documented with a comparison of degradation data for cells of different i-layer thickness, cells operating at open circuit vs. load, and for single vs. cascade cells. The model also correctly predicts the relation between short circuit current and fill factor degradation. At sufficiently long times, the efficiency will decrease at approximately the same rate for all cell structures and dimensions, with an offset in time between different device types which can be calculated.

Enhancing the energy conversion efficiency of low mobility solar cells by a 3D device architecture

2019 ◽  
Vol 7 (33) ◽  
pp. 10289-10296 ◽  
Author(s):  
Wayesh Qarony ◽  
Mohammad I. Hossain ◽  
Asman Tamang ◽  
Vladislav Jovanov ◽  
Alberto Salleo ◽  
...  
Keyword(s):  
Solar Cells ◽  
Energy Conversion ◽  
Amorphous Silicon ◽  
Conversion Efficiency ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Energy Conversion Efficiency ◽  
Semiconductor Materials ◽  
Device Architecture

The short circuit current and energy conversion efficiency of solar cells based on semiconductor materials with low diffusion lengths like organics and amorphous silicon can be increased by a 3D device architecture.

The influence of emitter resistance on the electrical parameters of mono- and multicrystalline silicon solar cells

2019 ◽  
Vol 36 (3) ◽  
pp. 90-94
Author(s):  
Barbara Swatowska ◽  
Piotr Panek ◽  
Dagmara Michoń ◽  
Aleksandra Drygała
Keyword(s):  
Solar Cells ◽  
Contact Resistance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Multicrystalline Silicon ◽  
Silicon Solar Cells ◽  
Electrical Parameters ◽  
Content Type ◽  
Diffusion Parameters

Purpose The purpose of this study was the comparison and analysis of the electrical parameters of two kinds of silicon solar cells (mono- and multicrystalline) of different emitter resistance. Design/methodology/approach By controlling of diffusion parameters, silicon mono- (Cz-Si) and multicrystalline (mc-Si) solar cells with different emitter resistance values were produced – 22 and 48 Ω/□. On the basis of current-voltage measurements of cells and contact resistance mapping, the properties of final solar cells based on two different materials were compared. Additionally, the influence of temperature on PV cells efficiency and open circuit voltage (Uoc) were investigated. The PC1D simulation was useful to determine spectral dependence of external quantum efficiency of solar cells with different emitter resistance. The silicon solar cells of 25 cm2 area and 240 µm thickness were investigated. Findings Considering the all stages of cell technology, the best structure is silicon solar cell with sheet resistance (Rsheet) of 45-48 Ω/□. Producing of an emitter with this resistance allowed to obtain cells with a fill factor between 0.725 and 0.758, Uoc between 585 and 612 mV, short circuit current (Isc) between 724 and 820 mA. Originality/value Measurements and analysis confirmed that mono- and multicrystalline silicon solar cells with 48 Ω/□ emitter resistance have better parameters than cells with Rsheet of 22 Ω/□. The contact resistance is the highest for mc-Si with Rsheet of 48 Ω/□ and reaches the value 3.8 Ωcm.

scholarly journals Nanomolded buried light-scattering (BLiS) back-reflectors using dielectric nanoparticles for light harvesting in thin-film silicon solar cells

2020 ◽  
Vol 11 ◽  
pp. 2
Author(s):  
Derese Desta ◽  
Rita Rizzoli ◽  
Caterina Summonte ◽  
Rui N. Pereira ◽  
Arne Nylandsted Larsen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Light Scattering ◽  
Silicon Nanoparticles ◽  
Short Circuit ◽  
Spatial Separation ◽  
Short Circuit Current ◽  
Silicon Solar Cells ◽  
Growth Interface ◽  
Inverted Pyramid ◽  
Back Reflector

The article presents a nanoparticle-based buried light-scattering (BLiS) back-reflector design realized through a simplified nanofabrication technique for the purpose of light-management in solar cells. The BLiS structure consists of a flat silver back-reflector with an overlying light-scattering bilayer which is made of a TiO2 dielectric nanoparticles layer with micron-sized inverted pyramidal cavities, buried under a flat-topped silicon nanoparticles layer. The optical properties of this BLiS back-reflector show high broadband and wide angular distribution of diffuse light-scattering. The efficient light-scattering by the buried inverted pyramid back-reflector is shown to effectively improve the short-circuit-current density and efficiency of the overlying n-i-p amorphous silicon solar cells up to 14% and 17.5%, respectively, compared to the reference flat solar cells. A layer of TiO2 nanoparticles with exposed inverted pyramid microstructures shows equivalent light scattering but poor fill factors in the solar cells, indicating that the overlying smooth growth interface in the BLiS back-reflector helps to maintain a good fill factor. The study demonstrates the advantage of spatial separation of the light-trapping and the semiconductor growth layers in the photovoltaic back-reflector without sacrificing the optical benefit.

The Effect of Al-BSF on Seff and Rb in Industrialized Mono-Silicon Solar Cells

2012 ◽  
Vol 472-475 ◽  
pp. 1846-1850
Author(s):  
Shan Shan Dai ◽  
Gao Jie Zhang ◽  
Xiang Dong Luo ◽  
Jing Xiao Wang ◽  
Wen Jun Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spectral Response ◽  
Short Circuit ◽  
Rear Surface ◽  
Surface Recombination ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Silicon Solar Cells ◽  
Back Surface

In this work, the effect of aluminum back surface field formed by screen printed various amount of Al paste on the effective rear surface recombination velocity (Seff) and the internal rear reflectance coeffeicient (Rb) of commercial mono-silicon solar cells was investigated. We demonstrated the effect of Seffand Rbon the performance of Al-BSF solar cells by simulating them with PC1D. The simulated results showed that the lower Seffcould get higher open circuit voltage (Voc), at the same time, the larger Rbcould get higher short-circuit current (Isc). Experimentally, we investigated the Seffand Rbthrough depositing Al paste with various amount (3.7, 5, 6, and 8 mg/cm2) for fabricating Al-BSF mono-silicon solar cells. Four group cells were characterized by light I-V, spectral response, hemispherical reflectance and scanning electron microscope (SEM) measurements. It was found that, a minimum Seffof 350 cm/s was gotten from the cells with Al paste of 8 mg/cm2, which was extracted by matching quantum efficiency (QE) from 800 nm to 1200 nm with PC1D, and a maximum Rbof 53.5% was obtained from Al paste of 5 mg/cm2by calculating at 1105 nm with PC1D. When the amount of Al paste was higher than 5mg/cm2, there were less Seffand lower Rb. On the other hand, when Al amount was 3.7mg/cm2, it was too little to form a closed BSF. Based on the SEM graphs and simulations with PC1D, a simple explaination was proposed for the experimental results.

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