scholarly journals Design and Investigation of SST/nc-Si:H/M (M = Ag, Au, Ni) and M/nc-Si:H/M Multifunctional Devices

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
A. F. Qasrawi ◽  
Salam M. Kmail ◽  
Samah F. Assaf ◽  
Z. M. Saleh

Hydrogenated nanocrystalline Silicon thin films prepared by the very high frequency chemical vapor deposition technique (VHF-CVD) on stainless steel (SST) substrates are used to design Schottky point contact barriers for the purpose of solar energy conversion and passive electronic component applications. In this process, the contact performance between SST and M (M = Ag, Au, and Ni) and between Ag, Au, and Ni electrodes was characterized by means of current-voltage, capacitance-voltage, and light intensity dependence of short circuit (Isc) current and open circuit voltage (Voc) of the contacts. Particularly, the devices ideality factors, barrier heights were evaluated by the Schottky method and compared to the Cheung's. Best Schottky device performance with lowest ideality factor suitable for electronic applications was observed in the SST/nc-Si:H/Ag structure. This device reflects a Voc of 229 mV with an Isc of 1.6 mA/cm2 under an illumination intensity of ~40 klux. On the other hand, the highest Isc being 9.0 mA/cm2 and the Voc of 53.1 mV were observed for Ni/nc-Si:H/Au structure. As these voltages represent the maximum biasing voltage for some of the designed devices, the SST/nc-Si:H/M and M/nc-Si:H/M can be regarded as multifunctional self-energy that provided electronic devices suitable for active or passive applications.

2010 ◽  
Vol 17 (03) ◽  
pp. 283-288 ◽  
Author(s):  
SANG-OK KIM ◽  
ALIAKSANDR KHODIN ◽  
JOONG KEE LEE

Hydrogenated amorphous and nanocrystalline silicon thin films were grown on porous anodic alumina substrates using electron cyclotron resonance-chemical vapor deposition technique from argon, hydrogen and silane gas composition. The structural characterization of the deposited hydrogenated silicon films were performed by scanning electron microscopy, Raman spectroscopy, and X-ray diffraction studies. The results revealed that mixed amorphous/nanocrystalline silicon phases with specific novel morphology were obtained on textured surfaces. The evolution of the film on ripple-like surface exhibited amorphous dominant structure, however, the film deposited on tipped/ribbed surface consisted of amorphous and nanocrystalline phases composite. The growth process strongly depends on the textured substrate pattern, which influences on the nanostructure shapes and crystallinity.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Taweewat Krajangsang ◽  
Sorapong Inthisang ◽  
Aswin Hongsingthong ◽  
Amornrat Limmanee ◽  
Jaran Sritharathikhun ◽  
...  

Optimization of p-type hydrogenated microcrystalline silicon oxide thin films (p-μc-Si1-xOx:H) by very high frequency plasma enhanced chemical vapor deposition 40 MHz method for use as a p-layer of a-Si:H solar cells was performed. The properties of p-μc-Si1-xOx:H films were characterized by conductivity, Raman scattering spectroscopy, and spectroscopic ellipsometry. The wide optical band gap p-μc-Si1-xOx:H films were optimized by CO2/SiH4ratio and H2/SiH4dilution. Besides, the effects of wide-gap p-μc-Si1-xOx:H layer on the performance of a-Si:H solar cells with various optical band gaps of p-layer were also investigated. Furthermore, improvements of open circuit voltage, short circuit current, and performance of the solar cells by using the effective wide-gap p-μc-Si1-xOx:H were observed in this study. These results indicate that wide-gap p-μc-Si1-xOx:H is promising to use as window layer in a-Si:H solar cells.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Jaran Sritharathikhun ◽  
Taweewat Krajangsang ◽  
Apichan Moollakorn ◽  
Sorapong Inthisang ◽  
Amornrat Limmanee ◽  
...  

This paper reports the preparation of wide gap p-type hydrogenated microcrystalline silicon oxide (p-μc-SiO:H) films using a 40 MHz very high frequency plasma enhanced chemical vapor deposition technique. The reported work focused on the effects of the CO2/SiH4ratio on the properties of p-μc-SiO:H films and the effectiveness of the films as an emitter layer of crystalline silicon heterojunction (c-Si-HJ) solar cells. A p-μc-SiO:H film with a wide optical band gap (E04), 2.1 eV, can be obtained by increasing the CO2/SiH4ratio; however, the tradeoff betweenE04and dark conductivity must be considered. The CO2/SiH4ratio of the p-μc-SiO:H emitter layer also significantly affects the performance of the solar cells. Compared to the cell using p-μc-Si:H (CO2/SiH4= 0), the cell with the p-μc-SiO:H emitter layer performs more efficiently. We have achieved the highest efficiency of 18.3% with an open-circuit voltage (Voc) of 692 mV from the cell using the p-μc-SiO:H layer. The enhancement in theVocand the efficiency of the solar cells verified the potential of the p-μc-SiO:H films for use as the emitter layer in c-Si-HJ solar cells.


2009 ◽  
Vol 1211 ◽  
Author(s):  
Ryo Morisawa ◽  
Akira Shirakura ◽  
Chen-Chung Du ◽  
Jen-Rong Huang ◽  
Muh-Wang Liang ◽  
...  

AbstractEffects of very high frequency- plasma enhanced chemical vapor deposition (VHF-PECVD) using diluted ultrapure silane at higher dilution ratio (R>30) on microstructures and optical characteristics of hydrogenated nanocrystalline silicon (nc-Si:H) film were studied. Nanocrystalline silicon films were prepared by at RF power ranging from 50 to 300 W. It was found that the transition from amorphous phase to nanocrystalline phase occurred between 100 W and 150 W. The nucleation mechanism toward nc-Si:H near the transition point of amorphous phase was discussed based on transmission electron microscopy with atomic scale. Further, it is suggested from UV-visible spectroscopy that nc-Si:H films with the best optical properties would be obtained near the transition point from the amorphous phase to the crystalline phase.


2008 ◽  
Vol 8 (8) ◽  
pp. 4211-4217 ◽  
Author(s):  
Sushil Kumar ◽  
Jhuma Gope ◽  
Aravind Kumar ◽  
A. Parashar ◽  
C. M. S. Rauthan ◽  
...  

Nanocrystalline silicon thin films were grown using gaseous mixture of 5% silane (SiH4) diluted in hydrogen (H2) and argon (Ar) in a radio frequency (13.56 MHz) plasma enhanced chemical vapor deposition technique. These films were deposited as a function of pressure and were characterized using AFM, Laser Raman, UV-VIS transmission, photoluminescence and electrical conductivity techniques. AFM micrographs shows that these films contain nanocrystallites of 30–60 nm size. Laser Raman peaks at 520 cm−1 and photoluminescence peaks at 2.75 and 2.85 eV have been observed. The crystalline fraction in these films was varied from 30% to 80% with the variation of deposition pressure from 2 Torr to 8 Torr. There is an optimum pressure of 4 Torr where the maximum growth of nanocrystalline phases was observed. It has been found that nanocrystallites in these film enhanced the optical band gap and electrical conductivity. Also a voltage–current (V–I) probe was used to evaluate the various electrical parameters of the plasma used to deposit the nc-Si:H films for the present investigation. Growth via a SiH3 precursor, diffusion of hydrogen in the sub-surface and argon etching of weak bonds are some of the processes that may be involved in the nano crystallization process.


2006 ◽  
Vol 20 (27) ◽  
pp. 1739-1747 ◽  
Author(s):  
QINGSONG LEI ◽  
ZHIMENG WU ◽  
XINHUA GENG ◽  
YING ZHAO ◽  
JIANPING XI

Hydrogenated silicon thin films (Si:H) have been deposited by using very high-frequency plasma-enhanced chemical vapor deposition (VHF PECVD). The structural, electrical and optical properties of the films were characterized. The transition process and the effect of pressure were studied. Results suggest that a narrow region, in which the transition from microcrystalline to amorphous growth takes place, exists in the regime of silane concentration (SC). This region is influenced by the working pressure (P). At lower pressure, the transition region is shifted to higher SC. Microcrystalline silicon (μ c-Si:H ) thin films deposited near transition region was applied as i-layer to the p-i-n solar cells. An efficiency of about 5.30% was obtained.


1997 ◽  
Vol 46 (10) ◽  
pp. 2015
Author(s):  
CHEN GUO ◽  
GUO XIAO-XU ◽  
ZHU MEI-FANG ◽  
SUN JING-LAN ◽  
XU HUAI-ZHE ◽  
...  

2009 ◽  
Vol 1153 ◽  
Author(s):  
Yuri Vygranenko ◽  
Ehsanollah Fathi ◽  
Andrei Sazonov ◽  
Manuela Vieira ◽  
Gregory Heiler ◽  
...  

AbstractWe report on structural, electronic, and optical properties of boron-doped, hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited by plasma-enhanced chemical vapor deposition (PECVD) at a substrate temperature of 150°C. Film properties were studied as a function of trimethylboron-to-silane ratio and film thickness. The film thickness was varied in the range from 14 to 100 nm. The conductivity of 60 nm thick films reached a peak value of 0.07 S/cm at a doping ratio of 1%. As a result of amorphization of the film structure, which was indicated by Raman spectra measurements, any further increase in doping reduced conductivity. We also observed an abrupt increase in conductivity with increasing film thickness ascribed to a percolation cluster composed of silicon nanocrystallites. The absorption loss of 25% at a wavelength of 400 nm was measured for the films with optimized conductivity deposited on glass and glass/ZnO:Al substrates. A low-leakage, blue-enhanced p-i-n photodiode with an nc-Si p-layer was also fabricated and characterized.


Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 759
Author(s):  
Luana Mazzarella ◽  
Anna Morales-Vilches ◽  
Lars Korte ◽  
Rutger Schlatmann ◽  
Bernd Stannowski

Doped hydrogenated nanocrystalline (nc-Si:H) and silicon oxide (nc-SiOx:H) materials grown by plasma-enhanced chemical vapor deposition have favourable optoelectronic properties originated from their two-phase structure. This unique combination of qualities, initially, led to the development of thin-film Si solar cells allowing the fabrication of multijunction devices by tailoring the material bandgap. Furthermore, nanocrystalline silicon films can offer a better carrier transport and field-effect passivation than amorphous Si layers could do, and this can improve the carrier selectivity in silicon heterojunction (SHJ) solar cells. The reduced parasitic absorption, due to the lower absorption coefficient of nc-SiOx:H films in the relevant spectral range, leads to potential gain in short circuit current. In this work, we report on development and applications of hydrogenated nanocrystalline silicon oxide (nc-SiOx:H) from material to device level. We address the potential benefits and the challenges for a successful integration in SHJ solar cells. Finally, we prove that nc-SiOx:H demonstrated clear advantages for maximizing the infrared response of c-Si bottom cells in combination with perovskite top cells.


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