Amorphous Crystalline Silicon Heterojunction with Silicon Nitride Buffer Layer

2000 ◽  
Vol 609 ◽  
Author(s):  
G. Claudio ◽  
R. De Rosa ◽  
F. Roca ◽  
D. Caputo ◽  
M. Tucci
Keyword(s):  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Wavelength Region ◽  
Visible Spectrum ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Deposition Parameters

ABSTRACTIn this work we study the possibility to use amorphous silicon nitride, grown by plasma, as an alternative way to realize buffer layer in a-Si:H/c-Si heterostructure. We experimented several growing condition for silicon nitride depending on deposition parameters, obtaining samples highly transparent and with optical gap varying in the range 2.4 – 5.2 eV. We found evidence that the gap of the material is principally due to the NH3/N2 ratio. The very low absorption obtainable on this material was successfully utilized to increase the short circuit current density of the device respect to the standard cell with intrinsic amorphous silicon buffer, particularly in the low wavelength region as confirmed by quantum yield measurements. We optimized the thickness of the SiNx buffer layer respect to the photovoltaic parameters of the solar cell. A 0.5 nm thick SiNx ensures good photogeneration in blue region of the visible spectrum and does not appreciably degrade the transport mechanism of the heterojunction.

Photogeneration and Carrier Transport in Amorphous Silicon/Crystalline Silicon Devices

1997 ◽  
Vol 467 ◽  
Author(s):  
B. Jagannathan ◽  
W. A. Anderson
Keyword(s):  
Amorphous Silicon ◽  
Carrier Transport ◽  
Crystalline Silicon ◽  
Plasma Deposition ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Silicon Devices

ABSTRACTHydrogenated amorphous silicon (a-Si:H)/ crystalline silicon (c-Si) type heterodiodes in solar cell structures have been studied by rf glow discharge, dc magnetron sputtering, and a remote plasma deposition of a-Si:H onto p type c-Si. Carrier transport and photogeneration in such structures have been investigated by current-voltage-temperature, thermally stimulated capacitance (TSCAP), and spectral response experiments. Dark carrier conduction is found to be a combination of tunneling and interface recombination, but is dominated by either one depending on the deposition/sputtering conditions. The conditions investigated include energy of the plasma species, type of plasma cleaning, and substrate preparation techniques. For each of the conditions, the trap type, energy and concentration have been identified by TSCAP. Solar cells fabricated by the optimized fabrication scheme routinely yield 10.5% efficient devices having a short circuit current density (Jsc) of 30 mA/cm2, a open circuit voltage of 0.55 volts and a fill factor (FF) of 0.64, without an AR coating, over 0.3 cm2 area.

Improving Performance of Amorphous Silicon Solar Cells Using Tungsten Oxide as a Novel Buffer Layer between the SnO2/p-a-SiC Interface

2010 ◽  
Vol 1245 ◽  
Author(s):  
Liang Fang ◽  
Seung Jae Baik ◽  
Koseng Su Lim ◽  
Seung Hyup Yoo ◽  
Myung Soo Seo ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Tungsten Oxide ◽  
Buffer Layer ◽  
Layer Structure ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Si Solar Cells ◽  
Photovoltaic Characteristics

AbstractA thermally evaporated p-type amorphous tungsten oxide (p-a-WO3) film was introduced as a novel buffer layer between SnO2 and p-type amorphous silicon carbide (p-a-SiC) of pin-type amorphous silicon (a-Si) based solar cells. By using this film, a-Si solar cells with a p-a-WO3/p-a-SiC double p-layer structure were fabricated and the cell photovoltaic characteristics were investigated as a function of p-a-WO3 layer thickness. By inserting a 2 nm-thick p-a-WO3 layer between SnO2 and a 6 nm-thick p-a-SiC layer, the short circuit current density increased from 9.73 to 10.57 mA/cm2, and the conversion efficiency was enhanced from 5.17 % to 5.98 %.

scholarly journals Over 30% efficiency bifacial 4-terminal perovskite-heterojunction silicon tandem solar cells with spectral albedo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangho Kim ◽  
Thanh Thuy Trinh ◽  
Jinjoo Park ◽  
Duy Phong Pham ◽  
Sunhwa Lee ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Solar Spectrum ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Production Costs ◽  
White Sand ◽  
Reflected Light

AbstractWe developed and designed a bifacial four-terminal perovskite (PVK)/crystalline silicon (c-Si) heterojunction (HJ) tandem solar cell configuration albedo reflection in which the c-Si HJ bottom sub-cell absorbs the solar spectrum from both the front and rear sides (reflected light from the background such as green grass, white sand, red brick, roofing shingle, snow, etc.). Using the albedo reflection and the subsequent short-circuit current density, the conversion efficiency of the PVK-filtered c-Si HJ bottom sub-cell was improved regardless of the PVK top sub-cell properties. This approach achieved a conversion efficiency exceeding 30%, which is higher than those of both the top and bottom sub-cells. Notably, this efficiency is also greater than the Schockley–Quiesser limit of the c-Si solar cell (approximately 29.43%). The proposed approach has the potential to lower industrial solar cell production costs in the near future.

Nanostructured Molybdenum Trioxide Layer on the Silver Anode of a Top-Incident Organic Photovoltaic Device

2021 ◽  
Vol 21 (3) ◽  
pp. 1659-1666
Author(s):  
Chia-Hsun Chen ◽  
Jiun Haw Lee ◽  
Chien-Liang Lin ◽  
Tien-Lung Chiu
Keyword(s):  
Buffer Layer ◽  
Deposition Rate ◽  
Fill Factor ◽  
Molybdenum Trioxide ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Organic Photovoltaic ◽  
20 Nm

A nanostructured molybdenum trioxide (MoO3) layer was successfully fabricated utilizing various deposition rates, employed as an anodic buffer layer to separate the active layer from a silver anode and modifying the anodic surface to facilitate hole transportation for top-incident organic photovoltaic (TIOPV) devices. The deposition rate and thickness of the MoO3 layer were crucial parameters for determining the surface morphology and work function, and the internal optical field distribution, respectively. These factors affected the performance of the devices in terms of their open-circuit voltage (VOC), short-circuit current density (JSC), and fill factor (FF). The baseline TIOPV device without a buffer layer had a power conversion efficiency (PCE) of only 0.47%. By contrast, with a smooth 20-nm MoO3 buffer layer fabricated using a deposition rate of 1 Å/s (which prevented problems caused by the Ag anode), another fabricated TIOPV device had substantially higher VOC, JSC and FF values, which improved the PCE by a factor of 6.2 to 2.92%. When an additional 5-nm nanostructured MoO3 layer was deposited at a deposition rate of 0.5 Å/s, the most efficient TIOPV device had an even greater PCE, a factor of 7.5 times higher at 3.53%.

scholarly journals Effect of the Phosphorus Gettering on Si Heterojunction Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hyomin Park ◽  
Sung Ju Tark ◽  
Chan Seok Kim ◽  
Sungeun Park ◽  
Young Do Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Current Density ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Solar Simulator ◽  
Heterojunction Solar Cells ◽  
Crystalline Silicon Solar Cells

To improve the efficiency of crystalline silicon solar cells, should be collected the excess carrier as much as possible. Therefore, minimizing the recombination both at the bulk and surface regions is important. Impurities make recombination sites and they are the major reason for recombination. Phosphorus (P) gettering was introduced to reduce metal impurities in the bulk region of Si wafers and then to improve the efficiency of Si heterojunction solar cells fabricated on the wafers. Resistivity of wafers was measured by a four-point probe method. Fill factor of solar cells was measured by a solar simulator. Saturation current and ideality factor were calculated from a dark current density-voltage graph. External quantum efficiency was analyzed to assess the effect of P gettering on the performance of solar cells. Minority bulk lifetime measured by microwave photoconductance decay increases from 368.3 to 660.8 μs. Open-circuit voltage and short-circuit current density increase from 577 to 598 mV and 27.8 to 29.8 mA/cm2, respectively. The efficiency of solar cells increases from 11.9 to 13.4%. P gettering will be feasible to improve the efficiency of Si heterojunction solar cells fabricated on P-doped Si wafers.

Employing μc-SiOX:H as n-Type Layer and Back TCO Replacement for High-Efficiency a-Si:H/μc-Si:H Tandem Solar Cells

2013 ◽  
Vol 1536 ◽  
pp. 33-38
Author(s):  
S.W. Liang ◽  
C.H. Hsu ◽  
Y.W. Tseng ◽  
Y.P. Lin ◽  
C.C. Tsai
Keyword(s):  
High Efficiency ◽  
Silicon Oxide ◽  
Short Circuit ◽  
Wavelength Region ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Microcrystalline Silicon ◽  
Tandem Solar Cells ◽  
Long Wavelength ◽  
Type Layer

ABSTRACTThe n-type hydrogenated microcrystalline silicon oxide (μc-SiOX:H(n)) films with different stoichiometry have been successfully prepared by varying the CO2-to-SiH4 flow ratio in the PECVD system. By using the μc-SiOX:H(n) as a replacement for μc-Si:H(n) and ITO, the conversion efficiency of μc-Si:H single-junction and a-Si:H/μc-Si:H tandem cells were improved to 6.35% and 10.15%, respectively. The major improvement of the short circuit current density (JSC) and these cell efficiencies were originated from the increased optical absorption, which was confirmed by the quantum efficiency measurement showing increased response in the long-wavelength region. Moreover, the all PECVD process except the metal contact simplified the fabrication and might benefit the industrial production.

Hydrogenated amorphous silicon germanium by Hot Wire CVD as an alternative for microcrystalline silicon in tandem and triple junction solar cells

2014 ◽  
Vol 1666 ◽  
Author(s):  
L.W. Veldhuizen ◽  
Y. Kuang ◽  
N.J. Bakker ◽  
C.H.M. van der Werf ◽  
S.-J. Yun ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Silicon Germanium ◽  
Short Circuit ◽  
Hydrogenated Amorphous Silicon ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

ABSTRACTWe study hydrogenated amorphous silicon germanium (a-SiGe:H) deposited by HWCVD for the use as low band gap absorber in multijunction junction solar cells. We deposited layers with Tauc optical band gaps of 1.21 to 1.56 eV and studied the hydrogen bonding with FTIR for layers that were deposited at several reaction pressures. For our reaction conditions, we found an optimal reaction pressure of 38 µbar. The material that is obtained under these conditions does not meet all device quality requirements for a-SiGe:H, which is, as we hypothesize, caused by the presence of He that is used to dilute the GeH4 source gas. We present an initial single junction n-i-p solar cell with a Tauc optical band gap of 1.45 eV and a short circuit current density of 18.7 mA/cm2.

scholarly journals Electro-Optical Characteristics of Shallow Silicon Junctions Fabricated Through Masked Ion Implantation

1985 ◽  
Vol 45 ◽  
Author(s):  
Andrei P. Silard
Keyword(s):  
Ion Implantation ◽  
Spectral Response ◽  
Short Circuit ◽  
Visible Spectrum ◽  
Short Circuit Current ◽  
Oxide Thickness ◽  
Short Circuit Current Density ◽  
Optical Characteristics ◽  
Technological Parameters ◽  
Large Bandwidth

ABSTRACTThe work presents the main electro-optical characteristics of very shallow silicon n+-p and P+-n junctions fabricated through masked ion implantation of phosphorus (31P+) and boron (11B+), respectively. The dependence of electro-optical characteristics on technological parameters (implant energy E and dose Q, oxide thickness Xox, impurity redistributions, etc.) are outlined in detail.The implant step was performed through a thermally-grown silicon dioxide (SiO2) mask of variable thickness (Xox = 100-1200 Å) at energies ranging from E=10 keV to 50 keV and with a dose level Q = 5 x 1014 - 2 x 1015 cm-2. As a rule, after the implant step the oxide layer was etched down. In several samples, the Si0 2 layer was preserved in the finished devices.The characterization of fabricated junctions was performed using a Karl Zeiss quartz prism monochromator coupled to a Tektronix 31/4661 data acquisition system. The main peculiar results could be summarized as follows: (a) all fabricated devices possess a relatively large bandwidth (up to 580 nm) of the relative spectral response; (b) for oxide thickness Xox Rp (projected range), the low energy implant yields devices with good blue response; (c) for Xox equal or larger than Rp a pronounced shift of the peak responsivity wavelength toward the visible spectrum of the light occurs; (d) a distinctive feature of devices consists in the high peak values of the short-circuit current density under AM1 insolation (in excess of 33 mA/cm2); (e) the preservation of SiO2 layer in the finished devices improves their electro-optical characteristics.

Optoelectronic Properties of Thin Amorphous and Micro-Crystalline p-Type Films Developed for Amorphous Silicon-Based Solar Cells

1996 ◽  
Vol 420 ◽  
Author(s):  
K. Winz ◽  
B. Rech ◽  
T. H. Eickhoff ◽  
C. Beneking ◽  
C. M. Fortmann ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Glass Substrates ◽  
Cell Structures ◽  
Silicon Carbon ◽  
P Type

AbstractVIIF-PECVD at 110 MI-z was used to deposit micro-crystalline p-layers on glass substrates for detailed analysis and onto ZnO coated substrates for incorporation into p-i-n solar cell structures. Solar cell and film analysis confirmed that the films incorporated into the solar cells contained significant crystalline silicon volume fractions despite being only 30 nm thick. The p-i-n solar cells employing a micro-crystalline silicon p-layer deposited on ZnO coated substrates had series resistances, fill factors and Voc similar to those of the reference solar cells deposited onto SnO2 coated substrates and having optimized amorphous silicon-carbon p-layers. The short circuit current of the micro-crystalline p-layer case was 10 percent lower than that of the reference cell indicating that further optimization is required.

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