A5007540333- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Copper-based nanomaterials and applications
- Semiconductor materials and interfaces
- Integrated Circuits and Semiconductor Failure Analysis
- Silicon and Solar Cell Technologies
- Semiconductor materials and devices
- Surface and Thin Film Phenomena
- Phase-change materials and chalcogenides
- Advanced Semiconductor Detectors and Materials
- ZnO doping and properties
- Metallurgical Processes and Thermodynamics
- solar cell performance optimization
- Calibration and Measurement Techniques
- Perovskite Materials and Applications
Toyota Central Research and Development Laboratories (Japan)
2015-2016
Aoyama Gakuin University
1998-2012
National Institute of Advanced Industrial Science and Technology
2003-2005
Yamato University
2004
Abstract To improve the photovoltaic properties of Cu 2 ZnSnS 4 (CZTS) cells, we investigated effect both thickness deposited CdS layers and post‐annealing temperature following deposition on CZTS cells using a two‐layer structure. By depositing thin layer (40 nm) followed by high annealing (603 K), observed remarkable increase in short‐circuit current density because enhancement external quantum efficiency wavelength range 400–800 nm. The best cell exhibited conversion 9.4% active area...
Wide-gap Cu(In 0.4 ,Ga 0.6 )Se 2 solar cells with Zn(O,S) buffer layers deposited by atomic layer deposition (ALD) technique have been investigated. The band-gap energy ( E g ) of the estimated optical transmission and reflection measurements was varied from 3.2 to 3.6 eV. sulfur (S)-poor showed a low open-circuit voltage V OC owing cliff nature conduction band offset (CBO). In contrast, S-rich short-circuit current density J SC spike CBO. Even if CBO values were adequate, best cell...
Abstract To improve the photovoltaic properties of Cu 2 ZnSnS 4 (CZTS) cells, we investigated use novel buffer layer materials. We found that Zn 1− x Sn O y fabricated by atomic deposition functioned as an effective layer. The short-circuit current density increased 10% because a decrease in absorption loss short-wavelength region. With 0.70 0.30 layers, conversion efficiency was 5.7%. reduce interface recombination, thin CdS inserted between ZnSnO and CZTS layers. cells using ZnSnO/CdS...
We have proposed the use of ZnO as a new buffer material in superstrate-type Cu(In, Ga)Se 2 (CIGS) solar cells. Little or no interdiffusion was found at ZnO/CIGS interface, allowing high temperatures for CIGS deposition. As result, cells with efficiencies reaching 10% were achieved first time by using this along inclusion sodium sulfide (Na S) during
We fabricated continuous highly (110)/(101)-oriented β-FeSi2 films on Si (111) substrates by the facing-target sputtering method. An epitaxial thin template buffer layer preformed silicon substrate was found to be essential in growth of thick films. It proved that reduced iron diffusion into during film fabrication. Even though annealing performed at high temperature (880 °C) for a long duration (10 h), effectively hindered template. By introducing this layer, an abrupt interface without...
Abstract We have investigated the influence of sodium (Na) on properties co‐evaporated Cu 2 ZnSnS 4 (CZTS) layer microstructures and solar cells. The photovoltaic performance diode were improved by incorporating Na from NaF layers into CZTS layers, while had a negligible effect microstructural layer. best cell fabricated using an optimal (Cu/(Zn + Sn) = 0.70, Zn/Sn 1.8) yielded active area efficiency 5.23%. analysis device suggests that charge‐carrier recombination at CZTS/CdS interface is...
The effects of substrate temperature (Tsub) and film thickness (dCIT) on the properties CuIn3Te5 thin films solar cells were investigated. (dCIT = 1.8–4.0 μm) grown both bare Mo-coated soda-lime glass substrates at Tsub 250–400 °C by single-step co-evaporation using a molecular beam epitaxy system. microstructural examined scanning electron microscopy x-ray diffraction. Well-developed (112)-oriented grains obtained increasing dCIT for 250 °C. Cathodoluminescence analysis...
High-efficiency cadmium-free Cu(In,Ga)Se 2 (CIGS) thin-film solar cells have been fabricated using a zinc compound buffer layer deposited by the chemical bath deposition (CBD) process. However, layers such as ZnS(O,OH) are prone to plasma-induced damage during subsequent ZnO sputtering A process causing less metal–organic vapor (MOCVD) is thus required for ZnO-based transparent conducting oxide (TCO) layers. In present work, boron-doped (ZnO:B) films were grown MOCVD diethyl (DEZ), H O, and...
ABSTRACT We propose CuIn 3 Te 5 as a ternary semiconductor material for narrow‐bandgap thin‐film solar cells. Well‐developed grains were obtained at substrate temperature of 250 °C by single‐step co‐evaporation. The best cell that was fabricated using 4·0‐µm‐thick layers grown yielded total area efficiency 6·92% ( V oc = 407 mV, J sc 33·1 mA/cm 2 , and FF 0·514). To clarify the loss in device performance, compared with standard CuInSe reference cell. A band diagram CdS/CuIn also presented....
Wide-gap Cu(In0.4,Ga0.6)Se2 solar cells with Zn(O,S) buffer layers deposited by atomic layer deposition (ALD) technique have been investigated. The band-gap energy (Eg) of the estimated optical transmission and reflection measurements was varied from 3.2 to 3.6 eV. sulfur (S)-poor showed a low open-circuit voltage (VOC) owing cliff nature conduction band offset (CBO). In contrast, S-rich short-circuit current density (JSC) spike CBO. Even if CBO values were adequate, best cell efficiencies...
The influence of Ga content and substrate temperature on the device performance CIGS thin film solar cells fabricated polyimide foils has been investigated. It was found that precise control in are important issues to achieve high-efficiency devices since these strongly affect formation double-graded bandgap structure. A desirable double-grading Ga/(In+Ga) atomic ratio formed with = 0.27 at a 480°C. By optimizing fabrication conditions best flexible cell yielded total-area efficiency 15.7% V...
Abstract The influence of the Zn/Sn atomic ratio on properties Cu–Zn–Sn–S-based film microstructure and solar cells was investigated. In addition to a small amount SnS, Cu 2 SnS 3 , ZnS coexisted in Zn-poor (Zn/Sn < 1) films, while ZnSnS 4 (CZTS) not formed. contrast, direct growth highly crystalline kesterite CZTS phase evident Zn-rich > which inevitably formed as secondary phase. Despite its coexistence with excess had negligible quality CZTS. Solar fabricated more films exhibited...
A multistage coevaporation process for the direct growth of Cu2ZnSnS4 (CZTS) thin films without additional atmospheric sulfurization was investigated. To obtain reproducible CZTS films, in situ monitoring film developed by measuring apparent substrate temperature (Tpyro) using a pyrometer. After depositions terminated at various endpoints, ex characterization properties performed to clarify mechanism films. The results provided clear evidence that phase formation significantly delayed via...
The effects of bismuth (Bi) incorporation into Cu(In 1- x ,Ga )Se 2 (CIGS) thin films and solar cells have been investigated. 10–50-nm-thick Bi layers were deposited onto Mo-coated soda-lime glass (SLG) SiO -coated SLG substrates by vacuum evaporation. CIGS then a three-stage process at substrate temperatures 450–550 °C. grain growth was enhanced, the open-circuit voltage hence conversion efficiency improved when used. However, little effect observed alkali barrier layer on substrates. As...
The effects of antimony (Sb) doping into Cu(In 1- x ,Ga )Se 2 (CIGS) thin films and solar cells have been investigated. 10–50-nm-thick Sb layers were deposited onto Mo-coated sodalime glass (SLG) SiO -coated SLG substrates by vacuum evaporation. CIGS then a three-stage process at substrate temperatures 450–550 °C. grain growth was enhanced, the open-circuit voltage hence conversion efficiency improved with when used. However, little or no effect observed alkali barrier layer on substrates....