A Novel Solar Cell Shallow Emitter Formation Process by Ion-Implantation and Dopant Modulation Through Surface Chemical Etching

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Wei-Lin Yang ◽  
Po-Hung Chen ◽  
Kun-Rui Wu ◽  
Likarn Wang
Keyword(s):  
Ion Implantation ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Advanced Technology ◽  
Surface Chemical ◽  
Recombination Rates ◽  
Selective Emitter ◽  
Novel Method ◽  
Wet Etch

Ion-implantation is an advanced technology to inject dopants for shallow junction formation. Due to the ion-induced sputtering effect at low implant energy where dopants tend to accumulate at the silicon surface, the excess ion doses can be easily removed via a surface chemical wet etching process. By taking advantage of the dose limitation characteristic, we proposed a novel method to form shallow emitters with various dopant densities. Two integration flows have been investigated: (1) wet etch after implantation before junction anneal and (2) wet etch after implantation and junction anneal. The two integration flows observed a difference in the density of doping impurities during the thermal process, which is related to the substrate recombination rates. Selective emitter (SE) structures with the two types of integration flows were characterized. Comparing the blanket emitter and SE structures with two types of etching methods, the device with wet etch before annealing process achieved the best effective carrier lifetime of 53.05 μs, which leads to a higher short circuit current density. Hence, this SE cell demonstrated a better blue response and shows an improvement in the conversion efficiency.

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.

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.

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.

scholarly journals The Influence of the Thickness of Compact TiO2 Electron Transport Layer on the Performance of Planar CH3NH3PbI3 Perovskite Solar Cells

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3295
Author(s):  
Andrzej Sławek ◽  
Zbigniew Starowicz ◽  
Marek Lipiński
Keyword(s):  
Solar Cells ◽  
Electron Transport ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Perovskite Solar Cells ◽  
Precursor Solution ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Transport Layer ◽  
Electron Transport Layer

In recent years, lead halide perovskites have attracted considerable attention from the scientific community due to their exceptional properties and fast-growing enhancement for solar energy harvesting efficiency. One of the fundamental aspects of the architecture of perovskite-based solar cells (PSCs) is the electron transport layer (ETL), which also acts as a barrier for holes. In this work, the influence of compact TiO2 ETL on the performance of planar heterojunction solar cells based on CH3NH3PbI3 perovskite was investigated. ETLs were deposited on fluorine-doped tin oxide (FTO) substrates from a titanium diisopropoxide bis(acetylacetonate) precursor solution using the spin-coating method with changing precursor concentration and centrifugation speed. It was found that the thickness and continuity of ETLs, investigated between 0 and 124 nm, strongly affect the photovoltaic performance of PSCs, in particular short-circuit current density (JSC). Optical and topographic properties of the compact TiO2 layers were investigated as well.

High short-circuit current density in a non-toxic Bi2S3 Quantum dot sensitized solar cell

2021 ◽  
pp. 100783
Author(s):  
Christopher Rosiles-Perez ◽  
Sirak Sidhik ◽  
Luis Ixtilico-Cortés ◽  
Fernando Robles-Montes ◽  
Tzarara López-Luke ◽  
...  
Keyword(s):  
Solar Cell ◽  
Quantum Dot ◽  
Current Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

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.

scholarly journals Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4268
Author(s):  
Jessica de Wild ◽  
Gizem Birant ◽  
Guy Brammertz ◽  
Marc Meuris ◽  
Jef Poortmans ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Electron Microscopic ◽  
Current Increase ◽  
Time Resolved ◽  
Cigs Solar Cells

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.

Enhancement of the performance of CdS/CdTe heterojunction solar cell using TiO2/ZnO bi-layer ARC and V2O5 BSF layers: A simulation approach

2020 ◽  
Vol 92 (2) ◽  
pp. 20901
Author(s):  
Abdul Kuddus ◽  
Md. Ferdous Rahman ◽  
Jaker Hossain ◽  
Abu Bakar Md. Ismail
Keyword(s):  
Solar Cell ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Heterojunction Solar Cell ◽  
Back Surface ◽  
Heterojunction Solar Cells

This article presents the role of Bi-layer anti-reflection coating (ARC) of TiO2/ZnO and back surface field (BSF) of V2O5 for improving the photovoltaic performance of Cadmium Sulfide (CdS) and Cadmium Telluride (CdTe) based heterojunction solar cells (HJSCs). The simulation was performed at different concentrations, thickness, defect densities of each active materials and working temperatures to optimize the most excellent structure and working conditions for achieving the highest cell performance using obtained optical and electrical parameters value from the experimental investigation on spin-coated CdS, CdTe, ZnO, TiO2 and V2O5 thin films deposited on the glass substrate. The simulation results reveal that the designed CdS/CdTe based heterojunction cell offers the highest efficiency, η of ∼25% with an enhanced open-circuit voltage, Voc of 0.811 V, short circuit current density, Jsc of 38.51 mA cm−2, fill factor, FF of 80% with bi-layer ARC and BSF. Moreover, it appears that the TiO2/ZnO bi-layer ARC, as well as ETL and V2O5 as BSF, could be highly promising materials of choice for CdS/CdTe based heterojunction solar cell.

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