Enhanced Light Absorption in a-Si:H Layers of Solar Cells by Applying Tco/Metal Back Contacts

1993 ◽  
Vol 297 ◽  
Author(s):  
G. Tao ◽  
B.S. Girwar ◽  
G.E.N. Landweer ◽  
M. Zeman ◽  
J.W. Metselaar
Keyword(s):  
Solar Cells ◽  
Metal Layer ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Back Contact ◽  
Flat Substrate ◽  
Metal Layers ◽  
Metal Back

The optimization of the back contact reflectivity for thin film a-Si:H solar cells has been performed. The results of optical calculations show that a-Si:H/TCO/Metal interfaces with a proper TCO thickness reflect much more than their a-Si:H/Metal counterparts. We compared solar cells which were deposited on a flat substrate with different back contacts. The back contacts consisted of a metal layer (aluminum, silver/aluminum) or combined TCO/metal layers (TCO/Al, TCO/Ag/Al). The same was done with solar cells which were deposited on a textured substrate. The solar cells with a TCO/metal back contact showed not only a significantly increased short-circuit current density but also an increase in the spectral response. The cells with TCO/Ag/Al back contact showed the best result.

Effect of CdCl2 Treatment of CdS Films on CdTe/CdS Solar Cells

1996 ◽  
Vol 426 ◽  
Author(s):  
W. Song ◽  
D. Mao ◽  
L. Feng ◽  
Y. Zhu ◽  
M. H. Aslan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spectral Response ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
X Ray Diffraction ◽  
Cdcl2 Treatment ◽  
The Difference ◽  
Cds Films

AbstractWe investigated the effect of CdCl2 treatment of CdS films on the photovoltaic performance of polycrystalline CdTe/CdS solar cells. X-ray diffraction studies indicated that the diffusion of S into CdTe is qualitatively the same for CdTe/CdS films fabricated with both as-deposited and CdCl2-treated CdS. A major difference was observed in the extent of Te diffusion into CdS for the two types of CdS films. Full conversion of CdS into CdS1-yTey; was observed for films prepared with asdeposited CdS, while the formation of the ternary phase was below the detection limit for films prepared with CdCl2-treated CdS. Photoluminescence measurements confirmed this result. The difference in interdiffusion leads to differences in optical transmission of CdS films and spectral response of CdTe/CdS solar cells. An increase of 2.7 mA/cm2 in short-circuit current density was observed as a result of improved spectral response in the wavelength range of 500–600 nm for the CdCl2-treated CdS.

Preparation of Narrow-gap a-Si:H Solar Cells by VHF-PECVD Technique

2010 ◽  
Vol 1245 ◽  
Author(s):  
Do Yun Kim ◽  
Ihsanul Afdi Yunaz ◽  
Shunsuke Kasashima ◽  
Shinsuke Miyajima ◽  
Makoto Konagai
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Solar Cell ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Hydrogen Flow ◽  
Long Wavelength

AbstractOptical, electrical and structural properties of silicon films depending on hydrogen flow rate (RH), substrate temperature (TS), and deposition pressure (PD) were investigated. By decreasing RH and increasing TS and PD, the optical band gap (Eopt) of silicon thin films drastically declined from 1.8 to 1.63 eV without a big deterioration in electrical properties. We employed all the investigated Si thin films for p-i-n structured solar cells as absorbers with i-layer thickness of 300 nm. From the measurement of solar cell performances, it was clearly observed that spectral response in long wavelength was enhanced as Eopt of absorber layers decreased. Using the solar cell whose Eopt of i-layer was 1.65 eV, the highest QE at long wavelength with the short circuit current density (Jsc) of 16.34 mA/cm2 was achieved, and open circuit voltage (Voc), fill factor (FF), and conversion efficiency (η) were 0.66 V, 0.57, and 6.13%, respectively.

scholarly journals Improving Efficiency of Evaporated Cu2ZnSnS4Thin Film Solar Cells by a Thin Ag Intermediate Layer between Absorber and Back Contact

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hongtao Cui ◽  
Chang-Yeh Lee ◽  
Wei Li ◽  
Xiaolei Liu ◽  
Xiaoming Wen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Carrier Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Depletion Region ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Back Contact ◽  
Secondary Phases ◽  
P Type

A 20 nm Ag coating on Mo back contact was adopted to improve the back contact of evaporated Cu2ZnSnS4(CZTS) solar cells. The Ag layer helped reduce the thickness of MoS2which improves fill factor (FF) significantly; additionally, it reduced secondary phases ZnS and SnS2−x, which may help carrier transport; it was also involved in the doping of the absorber layer, which compensated the intrinsic p-type doping and therefore drags down the doping level. The doping involvement may enlarge the depletion region and improve lifetime of the absorber, which led to enhancing open circuit voltage (VOC), short circuit current density (JSC), and efficiency significantly. However, it degrades the crystallinity of the material slightly.

scholarly journals Plasmonic Enhanced InP Nanowire Array Solar Cell through Optoelectronic Modeling

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 90
Author(s):  
Farzaneh Adibzadeh ◽  
Saeed Olyaee
Keyword(s):  
Solar Cells ◽  
Light Absorption ◽  
Metal Layer ◽  
Short Circuit ◽  
Nanowire Array ◽  
Solar Spectrum ◽  
Normal Incidence ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Middle Part

Vertical nanowire (NW) arrays are a promising candidate for the next generation of the optoelectronics industry because of their significant features. Here, we investigated the InP NW array solar cells and obtained the optoelectronic properties of the structure. To improve the performance of the NW array solar cells, we placed a metal layer of Au at the bottom of the NWs and considered their top part to be a conical-shaped parabola. Using optical and electrical simulations, it has been shown that the proposed structure improves the absorption of light in normal incidence, especially at wavelengths near the bandgap of InP, where photons are usually not absorbed. Under inclined radiation, light absorption is also improved in the middle part of the solar spectrum. Increased light absorption in the cell led to the generation of more electron–hole pairs, resulting in an increase in short circuit current density from 24.1 mA/cm2 to 27.64 mA/cm2, which is equivalent to 14.69% improvement.

scholarly journals Efficient Light Management in a Monolithic Tandem Perovskite/Silicon Solar Cell by Using a Hybrid Metasurface

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 791 ◽  
Author(s):  
Mahmoud H. Elshorbagy ◽  
Braulio García-Cámara ◽  
Eduardo López-Fraguas ◽  
Ricardo Vergaz
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Silicon Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Back Contact ◽  
Light Management ◽  
Promising Solution ◽  
Conversion Efficiencies

Solar energy is now dealing with the challenge of overcoming the Shockley–Queisser limit of single bandgap solar cells. Multilayer solar cells are a promising solution as the so-called third generation of solar cells. The combination of materials with different bandgap energies in multijunction cells enables power conversion efficiencies up to 30% at reasonable costs. However, interfaces between different layers are critical due to optical losses. In this work, we propose a hybrid metasurface in a monolithic perovskite-silicon solar cell. The design takes advantage of light management to optimize the absorption in the perovskite, as well as an efficient light guiding towards the silicon subcell. Furthermore, we have also included the effect of a textured back contact. The optimum proposal provides an enhancement of the matched short-circuit current density of a 20.5% respect to the used planar reference.

Solar Cells on Foreign Substrates Using Poly-Si Thin Films by Metal Induced Growth

2004 ◽  
Vol 808 ◽  
Author(s):  
Chunhai Ji ◽  
Wayne A. Anderson
Keyword(s):  
Solar Cells ◽  
Ion Implantation ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Doping Density ◽  
Charge Densities ◽  
Metal Induced Growth

ABSTRACTThe poly-Si film was deposited by using the metal-induced growth (MIG) method on tungsten substrates. By making Au/n-Si Schottky photo-diodes, doping density effect was studied by using three different doping level Si sputtering targets. Increasing the Si target resistivities from 0.02Ω-cm to 50Ω-cm, open-circuit-voltage (Voc) decreased from 0.22V to 0.14V while short-circuit-current density (Jsc) increased from 1.55mA/cm2 to 2.42mA/cm2. C-V results revealed a high charge density in the device, which may be due to the oxygen thermal donor effects. Using an oxygen filter for the sputtering gas effectively reduced the charge densities and increased the Jsc value. The p/n junction solar cells were fabricated by using ion implantation at 1013∼1014cm−2 dose and 100∼200keV. The cells with wider emitter layer by double-ion implantation gave higher Jsc and Voc values. Passivation of the Si film by using hydrogenation improved the Jsc, Voc and spectral response of the solar cells.

a-Si/c-Si Solar Cells: Effect of Preparation and Processing Techniques on the Photovoltaic Properties

1996 ◽  
Vol 426 ◽  
Author(s):  
B. Jagannathan ◽  
W. A. Anderson
Keyword(s):  
Solar Cells ◽  
Carrier Transport ◽  
Crystalline Silicon ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Photovoltaic Properties ◽  
Si Solar Cells ◽  
Processing Techniques

AbstractThe photovoltaic (PV) properties of undoped amorphous silicon (a-Si)/ p-type crystalline silicon (c-Si) solar cells were found to improve by a hydrofluoric acid treatment of c-Si just prior to glow discharge deposition of a-Si. The short circuit current density (Jsc) improved from 2.7 to 23.5 mA/cm2 for an 0.1 μm thick a-Si layer. This also resulted in an improved spectral response of the solar cell in the violet region of the spectrum. The enhanced properties have been attributed to the improved carrier transport across the interface, as seen in the current-voltage-temperature relationships, and also PC-1D simulation of the devices. Solar cells of a similar type were also fabricated by dc magnetron sputtering of the a-Si layer. HF passivated cells (area ∼ 0.24 cm2) yielded about 9.5 % efficiency with Jsc of 30 mA/cm2 and a FF of 0.6, without use of an A/R coating. The variation of the PV properties of these cells was investigated as a function of a-Si thickness and c-Si doping.

Determining the exciton diffusion length of copper phthalocyanine in operating planar-heterojunction organic solar cells

2020 ◽  
Vol 89 (3) ◽  
pp. 30201 ◽  
Author(s):  
Xi Guan ◽  
Shiyu Wang ◽  
Wenxing Liu ◽  
Dashan Qin ◽  
Dayan Ban
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Diffusion Length ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Thick Layer ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Organic solar cells based on planar copper phthalocyanine (CuPc)/C60 heterojunction have been characterized, in which a 2 nm-thick layer of bathocuproine (BCP) is inserted into the CuPc layer. The thin layer of BCP allows hole current to tunnel it through but blocks the exciton diffusion, thereby altering the steady-state exciton profile in the CuPc zone (zone 1) sandwiched between BCP and C60. The short-circuit current density (JSC) of device is limited by the hole-exciton scattering effect at the BCP/CuPc (zone 1) interface. Based on the variation of JSC with the width of zone 1, the exciton diffusion length of CuPc is deduced to be 12.5–15 nm. The current research provides an easy and helpful method to determine the exciton diffusion lengths of organic electron donors.

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