High hole drift mobility in a-Si:H deposited at high growth rates for solar cell application

Nanowires are ideal building blocks for next-generation solar cell applications. Nanowires grown with the selective area (SA) approach, in particular, have demonstrated very high material quality, thanks to high growth temperature, defect-free crystalline structure, and absence of external catalysts, especially in the InP material system. A comprehensive study on the influence of growth conditions and device processing on optical emission is still necessary though. This article presents an investigation of the nanowire optical properties, performed in order to optimize the internal radiative efficiency. In an initial preamble, the motivation for this study is discussed, as well as the morphology and crystallinity of the nanowires. The effect on the nanowire photoluminescence of several intrinsic and extrinsic parameters and factors are then presented in three sections: first, the influence of basic growth conditions such as the temperature and the precursor ratio is studied. Subsequently, the effects of varying dopant molar flows are explored, keeping in mind the intended solar cell application. Third, the manner in which the processing and the passivation affect the nanowire optical emission is discussed. Precise control of the growth conditions allows maximizing the nanowire internal radiative efficiency and thus their performance in solar cells and other optoelectronic devices.

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Optical Properties of i-Layers as a Function of Growth Rate in Correlation to the Performance of a-Si:H Solar Cells

MRS Proceedings ◽

10.1557/proc-715-a6.4 ◽

2002 ◽

Vol 715 ◽

Author(s):

Keda Wang ◽

Jessica M. Owens ◽

Jennifer Weinberg-Wolf ◽

Daxing Han ◽

Lynn Gedvilas

Keyword(s):

Growth Rate ◽

Optical Properties ◽

Hydrogen Bonding ◽

Solar Cells ◽

Solar Cell ◽

Growth Rates ◽

High Growth ◽

Solar Cell Performance ◽

Bonding Configuration ◽

Small Absorption

Abstracta-Si:H intrinsic films and their solar cells were prepared by DC-PECVD with growth rates of 1, 3, and 10 Å/s. Raman, IR, and PL spectroscopies were used to study the i-layer properties in relation to the solar cell performance. Raman shows an identical TO mode for all the samples, which indicates the local silicon-bonding configuration does not change with the growth rate from 1 to 10 Å/s. IR results show that the hydrogen bonding configuration is monohydride (Si-H) dominated, and the hydrogen content obtained from the 630 cm-1 wagging mode is 12-14 at.%. Surprisingly, a very small absorption strength for the stretching 2000-2100 cm-1 mode was found for some samples deposited at the higher growth rates (3, 10 Å/s). For these same samples, the PL spectra exhibit a red shift. Both the IR and PL results might be related to the same microstructures formed at high growth rates. We found that although the properties of the i-layer varied as the growth rate increased from 1 to 10 Å/s, the performances of the cells were comparable (within about 4%).

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Hydrogen Injection in ETP Plasma Jet for Fast-Deposition of High-Quality a-Si:H

MRS Proceedings ◽

10.1557/proc-808-a9.54 ◽

2004 ◽

Vol 808 ◽

Author(s):

A.M.H.N. Petit ◽

R.A.C.M.M. van Swaaij ◽

M.C.M. van de Sanden

Keyword(s):

Growth Rate ◽

Hydrogen Content ◽

Growth Rates ◽

Plasma Chemistry ◽

High Growth ◽

Plasma Jet ◽

Solar Cell Application ◽

Microstructure Parameter ◽

Strong Relation ◽

Defect Densities

ABSTRACTWe have used a cascaded-arc expanding thermal plasma (ETP) to produce thin films of amorphous silicon at high growth rates (> 3 nm/s). Here, we present a study of the effect on material properties of hydrogen injection in the nozzle, i.e., at the exit of the arc where the plasma expands into the reactor chamber. The advantage of using extra H2 in the nozzle is that the plasma chemistry and pressure in the arc remain unchanged, whilst higher growth rates and a material with low defect densities can be obtained.We observe that with an increase of substrate temperature the growth rate decreases due to densification of the material. This densification is accompanied by a reduction of the hydrogen content and of the microstructure parameter. Further we observe that hydrogen content decreases with higher growth rate. A strong relation is found between the light conductivity and the microstructure parameter indicating a large void fraction in samples grown at low temperature.We have been able to grow a-Si:H material, with H2 in the nozzle, at 350°C and 3 nm/s with a light conductivity of 1.2 × 10−5 Ω1cm−1, which can be suitable for solar-cell application.

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GROWTH OF PIKE-PERCH SANDER LUCIOPERCA (L., 1758) (PERCIDAE) IN RESERVOIRS OF K. SATPAYEV’S CHANNEL

VESTNIK OF ASTRAKHAN STATE TECHNICAL UNIVERSITY SERIES FISHING INDUSTRY ◽

10.24143/2073-5529-2018-1-59-68 ◽

2018 ◽

pp. 59-68

Author(s):

Saule Zhangirovna Asylbekova ◽

Kuanysh Baibulatovich Isbekov ◽

Vladimir Nickolaevich Krainyuk

Keyword(s):

Growth Rates ◽

Growth Dynamics ◽

High Growth ◽

Water Bodies ◽

Volga River ◽

Trophic Resources ◽

Pike Perch ◽

The Amur River ◽

Back Calculation ◽

Abiotic And Biotic Factors

Pike-perch is an invader for the water basins of Central Kazakhstan. These species have stable self-reproductive populations in the regional waters. Back calculation method was used to investigate pike-perch growth rates in reservoirs of K. Satpayev’s channel. For comparison, the data from the other water bodies (Vyacheslavsky and Sherubay-Nurinsky water reservoirs) were used, as well as literature data. Pike-perch species from the investigated waters don’t show high growth rates. The populations from the reservoirs of K. Satpayev’s channel have quite similar growth rates with populations from the Amur river, from a number of reservoirs in the Volga river basin and from the reservoir in Spain. Sexual differences in growth have not been observed. Evaluating possible influence of various abiotic and biotic factors on the growth rate of pike-perch in the reservoirs of K. Satpayev’s channel was carried out. It has been stated that the availability of trophic resources cannot play a key role in growth dynamics because of their high abundance. Morphology of water bodies also does not play a role, as well as chromaticity, turbidity and other optical water indicators. It can be supposed that the main factor influencing growth of pike perch is the habitat’s temperature. This factor hardly ever approaches optimal values for the species in reservoirs of K. Satpaev’s channel. The possible influence of fishing selectivity on pike-perch growth rates was also evaluated. Currently, there has been imposed a moratorium on pike-perch catch. However, pike-perch is found in by-catches and in catches of amateur fishermen. It should be said that such seizures have an insignificant role in the dynamics of growth rates.

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