Mechanism of the Improvement in Microcrystalline Silicon Solar Cells by Hydrogen Plasma Treatment

2013 ◽  
Vol 773 ◽  
pp. 118-123
Author(s):  
Jing Yan Li ◽  
Xiang Bo Zeng ◽  
Hao Li ◽  
Xiao Bing Xie ◽  
Ping Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Plasma Treatment ◽  
Defect Density ◽  
Hydrogen Plasma ◽  
Microcrystalline Silicon ◽  
One Dimensional ◽  
Long Wavelength ◽  
Drift Length ◽  
Experimental Improvement

We explain the experimental improvement in long wavelength response by hydrogen plasma treatment (HPT) in n/i interface. The absorption coefficient of the intrinsic microcrystalline silicon (μc-Si) is decreased in the low energy region (0.8~1.0 eV) by HPT, which indicates a lower defect density in μc-Si layer deposited with HPT than its counterpart without HPT. Simulation by one-dimensional device simulation program for the Analysis of Microelectronic and Photonic Structures (AMPS-1D) shows a higher long wavelength response in μc-Si solar cell if the defect density in intrinsic μc-Si layer is smaller. Our simulation results also disclose that the less defect density in intrinsic layer, the lower recombination rate and the higher electric field is. Higher electric field results in longer drift length which will promote collection of carriers generated by photons with long wavelength. Thus we deduce that HPT decreased defect density in absorber layer and improved the performance of μc-Si solar cells in long wavelength response.

Improvement in Wide-Gap A-SI:H For High-Efficiency Solar Cells

1992 ◽  
Vol 258 ◽  
Author(s):  
Sadaji Tsuge ◽  
Yoshihiro Hishikawa ◽  
Shingo Okamoto ◽  
Manabu Sasaki ◽  
Shinya Tsuda ◽  
...  
Keyword(s):  
Solar Cells ◽  
Plasma Treatment ◽  
High Efficiency ◽  
Defect Density ◽  
Hydrogen Plasma ◽  
Wide Band ◽  
Open Circuit ◽  
Wide Band Gap ◽  
High Efficiency Solar Cells ◽  
Wide Gap

ABSTRACTA hydrogen-plasma treatment has been used for the first time to fabricate wide-gap, high-quality a-Si:H films. The hydrogen content (CH) of a-Si:H films substantially increases by the hydrogen-plasma treatment after deposition, without deteriorating the opto-electric properties of the films. The photoconductivity (σph) of ≥ 10-5 ο-1 cm-1, photosensitivity ( σ ph/σ d) of > 106 and SiH2/SiH of <0.2 are achieved for a film with CH of ∼25 atomic >%. The optical gap of the film is > 1.70 eV by the (α h ν )1/3 plot, and is >2 eV by the Tauc's plot. The open circuit voltage of a-Si solar cells exceeds 1 V conserving the fill factor of > 0.7 when the wide-gap a∼Si:H films are used as the i-layer, which proves the wide band gap and low defect density.

Reduced defect density in microcrystalline silicon by hydrogen plasma treatment

2013 ◽  
Vol 34 (10) ◽  
pp. 103006
Author(s):  
Jingyan Li ◽  
Xiangbo Zeng ◽  
Hao Li ◽  
Xiaobing Xie ◽  
Ping Yang ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Defect Density ◽  
Hydrogen Plasma ◽  
Microcrystalline Silicon

DEVELOPMENT OF HIGHLY CONDUCTIVE P-TYPE MICROCRYSTALLINE SILICON FILMS FOR N–I–P FLEXIBLE SOLAR CELLS APPLICATION

2010 ◽  
Vol 24 (28) ◽  
pp. 5527-5538 ◽  
Author(s):  
Q. S. LEI ◽  
H. X. XU ◽  
J. P. XU
Keyword(s):  
Solar Cells ◽  
Plasma Treatment ◽  
Amorphous Silicon ◽  
Treatment Time ◽  
Hydrogen Plasma ◽  
Dark Conductivity ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Nucleation Layer ◽  
P Type

In this paper, we reported highly conductive p-type microcrystalline silicon (μc- Si:H ) films deposited on amorphous silicon (a- Si:H ) surface by very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) technique. Hydrogen plasma treatment of amorphous silicon surface and nucleation layers were introduced prior to μc- Si:H films deposition. The film properties were investigated by using Raman spectra, scanning electron microscope (SEM), optical transmission and reflection, as well as dark conductivity measurements. The influence of plasma treatment and nucleation layer on the growth and properties of the thin p-type μc- Si:H films was studied. It is demonstrated that the hydrogen plasma treatment of a- Si:H films gives rise to the deposition of μc- Si:H on the a- Si:H surface. Also, the growth and properties of the μc- Si:H films are strongly dependent on the nucleation layer. The dark conductivity (σd) and crystalline fraction increase with the plasma treatment time and attain high values at about 600 s. A p-type μc- Si:H film with conductivity of 0.0875 Scm-1 at a thickness of 30 nm was obtained. The film was introduced as window layers for flexible solar cells. An efficiency of about 7.15% was obtained.

Dry Passivation Process for Silicon Heterojunction Solar Cells Using Hydrogen Plasma Treatment Followed by In Situ a-Si:H Deposition

2018 ◽  
Vol 8 (6) ◽  
pp. 1539-1545 ◽  
Author(s):  
Menglei Xu ◽  
Chong Wang ◽  
Twan Bearda ◽  
Eddy Simoen ◽  
Hariharsudan Sivaramakrishnan Radhakrishnan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Plasma Treatment ◽  
Hydrogen Plasma ◽  
Heterojunction Solar Cells ◽  
Passivation Process ◽  
Silicon Heterojunction Solar Cells

Hydrogen plasma treatment for improving bulk passivation quality of c-Si solar cells

2010 ◽  
Vol 10 (2) ◽  
pp. S215-S217 ◽  
Author(s):  
Suttirat Rattanapan ◽  
Hiroshi Yamamoto ◽  
Shinsuke Miyajima ◽  
Takehiko Sato ◽  
Makoto Konagai
Keyword(s):  
Solar Cells ◽  
Plasma Treatment ◽  
Hydrogen Plasma ◽  
Si Solar Cells ◽  
Bulk Passivation

Influence of Pressure and Plasma Potential on High Growth Rate Microcrystalline Silicon Grown by Vhf Pecvd

2005 ◽  
Vol 862 ◽  
Author(s):  
A. Gordijn ◽  
J. Francke ◽  
L. Hodakova ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Solar Cells ◽  
High Pressures ◽  
Defect Density ◽  
Plasma Potential ◽  
High Rate ◽  
Growth Surface ◽  
Microcrystalline Silicon ◽  
Ion Energy ◽  
Single Junction ◽  
External Power Source

AbstractMicrocrystalline silicon (μc-Si) based single junction solar cells are deposited by VHF PECVD using a showerhead cathode at high pressures in depletion conditions. At a deposition rate of 4.5 nm/s, a stabilized conversion efficiency of 6.7 % is obtained for a single junction solar cell with a μc-Si i-layer of 1 μm. The i-layer is made near the transition from amorphous to crystalline. In order to control the material properties in the growth direction, the hydrogen dilution of silane in the gas phase is graded following different profiles with a parabolic shape. It is observed that the performance of solar cells deposited at high rate improves under light soaking conditions at 50 °C, which we attribute to post deposition equilibration of a fast deposited transition material.The performance is lower at higher rates due to poorer i-layer quality (higher defect density), which may be attributed to smaller relaxation times for growth precursors at the growth surface and the higher energy ion bombardment at higher plasma power. High process pressures can be used to reduce the ion energy by decreasing the mean free path. We have introduced an additional method to limit the ion energy by controlling the DC self bias voltage using an external power source. In this way the quality of the μc-Si layers and the performance of the solar cells is further improved.

scholarly journals Development of Hydrogenated Microcrystalline Silicon-Germanium Alloys for Improving Long-Wavelength Absorption in Si-Based Thin-Film Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yen-Tang Huang ◽  
Hung-Jung Hsu ◽  
Shin-Wei Liang ◽  
Cheng-Hang Hsu ◽  
Chuang-Chuang Tsai
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Silicon Germanium ◽  
Volume Fraction ◽  
Thin Film Solar Cells ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Single Junction ◽  
Long Wavelength ◽  
Wavelength Absorption

Hydrogenated microcrystalline silicon-germanium (μc-Si1-xGex:H) alloys were developed for application in Si-based thin-film solar cells. The effects of thegermane concentration(RGeH4)and thehydrogen ratio(RH2)on theμc-Si1-xGex:H alloys and the corresponding single-junction thin-film solar cells were studied. The behaviors of Ge incorporation in a-Si1-xGex:H andμc-Si1-xGex:H were also compared. Similar to a-Si1-xGex:H, the preferential Ge incorporation was observed inμc-Si1-xGex:H. Moreover, a higherRH2significantly promoted Ge incorporation for a-Si1-xGex:H, while the Ge content was not affected byRH2inμc-Si1-xGex:H growth. Furthermore, to eliminate the crystallization effect, the 0.9 μm thick absorbers with a similar crystalline volume fraction were applied. With the increasingRGeH4, the accompanied increase in Ge content ofμc-Si1-xGex:H narrowed the bandgap and markedly enhanced the long-wavelength absorption. However, the bias-dependent EQE measurement revealed that too much Ge incorporation in absorber deteriorated carrier collection and cell performance. With the optimization ofRH2andRGeH4, the single-junctionμc-Si1-xGex:H cell achieved an efficiency of 5.48%, corresponding to the crystalline volume fraction of 50.5% and Ge content of 13.2 at.%. Compared toμc-Si:H cell, the external quantum efficiency at 800 nm had a relative increase by 33.1%.

Influence of ultrathin amorphous silicon layers on the nucleation of microcrystalline silicon films under hydrogen plasma treatment

2011 ◽  
Vol 98 (4) ◽  
pp. 041902 ◽  
Author(s):  
Z. W. Zuo ◽  
W. T. Guan ◽  
Y. Wang ◽  
J. Lu ◽  
J. Z. Wang ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Amorphous Silicon ◽  
Hydrogen Plasma ◽  
Silicon Films ◽  
Microcrystalline Silicon
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