A novel type of n/i/i/p heterojunction solar cell with a-Si:H(15 nm)/a-Si:H(10 nm)/ epitaxial c-Si(47 μm)/epitaxial c-Si(3 μm) structure is fabricated by using the layer transfer technique, and the emitter layer is deposited by hot-wire chemical vapour deposition. The effect of the doping concentration of emitter layer Sd (Sd=PH3/(PH3+SiH4+H2)) on the performance of the solar cell is studied by means of current density-voltage and external quantum efficiency. The results show that the conversion efficiency of the solar cell first increases to a maximum value and then decreases with Sd increasing from 0.1% to 0.4%. The best performance of the solar cell is obtained at Sd = 0.2% with an open circuit voltage of 534 mV, a short circuit current density of 23.35 mA/cm2, a fill factor of 63.3%, and a conversion efficiency of 7.9%. 相似文献
Microcrystalline silicon thin film pin solar cells with a highly crystallized intrinsic μc‐Si:F:H absorber were prepared by RF‐plasma enhanced chemical vapour deposition using SiF4 as the gas precursor. The cells were produced with a vacuum break between the doped layer and intrinsic layer depositions, and the effect of different subsequent interface treatment processes was studied. The use of an intrinsic μc‐Si:H p/i buffer layer before the first air break increased the short circuit current density from 22.3 mA/cm2 to 24.7 mA/cm2. However, the use of a hydrogen‐plasma treatment after both air breaks without an interface buffer layer improved both the open circuit voltage and the fill factor. Although the material used for the absorber layer showed a very high crystalline fraction and thus an increased spectral response at long wavelengths, an open‐circuit voltage (VOC) of 0.523 V was nevertheless observed. Such a value of VOC is higher than is typically obtained in devices that employ a highly crystallized absorber as reported in the literature (see abstract figure). Using a hydrogen‐plasma treatment, a single junction μc‐Si:F:H pin solar cell with an efficiency of 8.3% was achieved.
Precise patterning by laser ablation requires sufficient absorption. For weak absorbers like fused silica indirect methods
using external absorbers have been developed. A novel approach using a solid SiO absorber coating is described. Irradiation
by an ArF excimer laser (wavelength 193 nm) is leading to ablation of the coating and, at sufficiently high fluence, of the
fused silica substrate. The remaining coating in the unexposed areas is removed afterwards by large area irradiation. The
fluence threshold for substrate ablation using a 28 nm thick absorber layer is about 1.1 J/cm2. Single pulse ablation rates of up to 800 nm and a surface roughness of Ra<5 nm are obtained. High resolution grating patterns with 400 nm period and a modulation depth of 80 nm are possible. The
process can be described as controlled plasma mediated ablation. 相似文献
Flexible Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells were fabricated on stainless steel foil by using aqueous spray deposition method. Since stainless steel foil is used, external alkali doping is necessary to passivate defects in CIGSSe absorber. We investigated effects of (Na, K) co-doping and selenization temperature on solar cell performance. With co-doping of Na and K, defect states were passivated significantly and highest power conversion efficiency (PCE) was obtained. However, at higher K concentration of more than 0.5%, different growth mode of CIGSSe was observed and deep defect states were developed, decreasing PCE. In addition, selenization temperature effects were studied by varying selenization temperatures. With higher selenization temperature, defect passivation for the CIGSSe absorber was more apparent, which facilitated increase of open circuit voltage. However, short circuit current was observed to be decreased at higher selenization temperature of 570 °C. This work demonstrates in-situ alkali co-doping into CIGSSe absorber with simple and low-cost spray deposition in an air environment. 相似文献
Continuous growth of the thin-film electronics market stimulates the development of versatile technologies for large-scale
patterning of thin-film materials on rigid and flexible substrates, and laser technologies are a promising method to accomplish
the scribing processes. Lasers with picosecond pulse duration were applied in scribing of complex multilayered CuInxGa(1−x)Se2 (CIGS) solar cells deposited on a polyimide substrate. The ablative properties of the films were examined as a function of
the wavelength of laser radiation, pulse energy, and the irradiation dose. The selective removal of ITO and CIGS layers was
achieved with 355 nm irradiation without any significant damage to the underlying layers in the ITO/CIGS/Mo/PI solar cell
system. The 355 nm wavelength was also found to be favorable for scribing of absorber layer in a ZnO/CIGS/Mo/PI solar cell
system. 266 nm radiation significantly modified the film structure due to high absorption. Extensive melt formation in the
CIGS layer was found when 532 nm radiation was applied, though the trenches were smooth and crack-free. 相似文献
Thick metals are nearly opaque due to high reflectance and the huge third-order nonlinear susceptibility of metals is hardly
utilized. In the present paper, zero-reflection phenomena in a thick metal (M) slab covered with one-dimensional dielectric
photonic crystals (PC’s) (CD)n are studied in heterostructures M(DC)n and sandwiched structures (CD)nM(DC)n. Visible-light tunneling modes can be realized in M(DC)n or (CD)nM(DC)n in which the optical epsilon-negative medium (metal) is paired with the PC, which mimics a lossless optical mu-negative medium
in the gap region. The transmittance as high as 33% and 38% are observed at wavelength of 589 nm for M = Ag, with thickness
d=60.2 nm in a heterostructure and d=83.1 nm in a sandwiched structure, respectively. The transmittance is more than 200 times larger than that of a single Ag
layer with the same thickness in the latter case. Possible applications on metal-based nonlinearity enhancement and optical
absorber are also discussed. 相似文献
Solar modules and arrays are the conventional energy resources of space satellites. Outside the earth's atmosphere, solar panels experience abnormal radiation environments and because of incident particles, photovoltaic (PV) parameters degrade. This article tries to analyze the electrical performance of electron and photon-irradiated mono-crystalline silicon (mono-Si) solar cells. PV cells are irradiated by mono-energetic electrons and poly-energetic photons and immediately characterized after the irradiation. The mean degradation of the maximum power (Pmax) of silicon solar cells is presented and correlated using the displacement damage dose (Dd) methodology. This method simplifies evaluation of cell performance in space radiation environments and produces a single characteristic curve for Pmax degradation. Furthermore, complete analysis of the results revealed that the open-circuit voltage (Voc) and the filling factor of mono-Si cells did not significantly change during the irradiation and were independent of the radiation type and fluence. Moreover, a new technique is developed that adapts the irradiation-induced effects in a single-cell equivalent electrical circuit and adjusts its elements. The “modified circuit” is capable of modeling the “radiation damage” in the electrical behavior of mono-Si solar cells and simplifies the designing of the compensation circuits. 相似文献
Recent study shows that the main reason for limiting CZTS device performance lies in the low open circuit voltage, and crucial factor that could affect the Voc is secondary phases like ZnS existing in absorber layer and its interfaces. In this work, the Cu2ZnSnS4 thin film solar cells were prepared by sputtering CuSn and CuZn alloy targets. Through tuning the Zn/Sn ratios of the CZTS thin films, the crystal structure, morphology, chemical composition and phase purity of CZTS thin films were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and Raman spectroscopy. The statistics data show that the CZTS solar cell with a ratio of Zn/Sn = 1.2 have the best power convention efficiency of 5.07%. After HCl etching process, the CZTS thin film solar cell with the highest efficiency 5.41% was obtained, which demonstrated that CZTS film solar cells with high efficiency could be developed by sputtering CuSn and CuZn alloy targets. 相似文献