Thin Film Poly-Si Solar Cell on Glass Substrate Fabricated at Low Temperature

1998 ◽  
Vol 507 ◽  
Author(s):  
Kenji Yamamoto ◽  
Masashi Yoshimi ◽  
Takayuki Suzuki ◽  
Yuko Tawada ◽  
Yoshifumi Okamoto ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Glass Substrate ◽  
Spectral Response ◽  
Chemical Vapor ◽  
Open Circuit ◽  
Reflectance Measurement ◽  
Long Wavelength ◽  
Enhanced Absorption ◽  
Back Reflector

ABSTRACTThe performances of thin film poly-Si solar cells with a thickness of less than 5 μm on a glass substrate have been investigated. The cell of glass / back reflector / n-i-p type Si / ITO is well characterized by the structure of naturally _surface texture and enhanced absorption with a back reflector (STAR), where the active i-type poly-Si layer was fabricated by plasma chemical vapor deposition (CVD) at low temperature. The cell with a thickness of 2.0 μm demonstrated an intrinsic efficiency of 10.7% (aperture 10.1%), the open circuit voltage of 0.539 V and the short current density of 25.8 mA/cm2 as independently confirmed by Japan Quality Assurance. The optical confinement effect explains the excellent spectral response at long wavelength for our cells through the PCID analysis. The higher sensitivity at long-wavelength of our cell appeared in quantum efficiency curves is well correlated to the result of reflectance measurement. The efficiency of 9.3% cell with a thickness of 1.5 pm was proved to be entirely stable with respect to the lightsoaking. Based on the result of various evaluation of diffusion length, it is postulated that the low temperature poly-Si prepared by plasma CVD gives a device quality of poly-Si film.

Precursor design and engineering for low-temperature deposition of gate dielectrics for thin film transistors

2011 ◽  
Vol 1287 ◽  
Author(s):  
Anupama Mallikarjunan ◽  
Laura M Matz ◽  
Andrew D Johnson ◽  
Raymond N Vrtis ◽  
Manchao Xiao ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Thin Film Transistors ◽  
Moisture Absorption ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Silicon Oxycarbide ◽  
Process Conditions ◽  
Structure Property ◽  
Oh Groups

ABSTRACTThe electrical and physical quality of gate and passivation dielectrics significantly impacts the device performance of thin film transistors (TFTs). The passivation dielectric also needs to act as a barrier to protect the TFT device. As low temperature TFT processing becomes a requirement for novel applications and plastic substrates, there is a need for materials innovation that enables high quality plasma enhanced chemical vapor deposition (PECVD) gate dielectric deposition. In this context, this paper discusses structure-property relationships and strategies for precursor development in silicon nitride, silicon oxycarbide (SiOC) and silicon oxide films. Experiments with passivation SiOC films demonstrate the benefit of a superior precursor (LkB-500) and standard process optimization to enable lower temperature depositions. For gate SiO2 deposition (that are used with polysilicon TFTs for example), organosilicon precursors containing different types and amounts of Si, C, O and H bonding were experimentally compared to the industry standard TEOS (tetraethoxysilane) at different process conditions and temperatures. Major differences were identified in film quality especially wet etch rate or WER (correlating to film density) and dielectric constant (k) values (correlating to moisture absorption). Gate quality SiO2 films can be deposited by choosing precursors that can minimize residual Si-OH groups and enable higher density stable moisture-free films. For e.g., the optimized precursor AP-LTO® 770 is clearly better than TEOS for low temperature PECVD depositions based on density, WER, k charge density (measured by flatband voltage or Vfb); and leakage and breakdown voltage (Vbd) measurements. The design and development of such novel precursors is a key factor to successfully enable manufacturing of advanced low temperature processed devices.

scholarly journals Low Temperature Sub-micron Gap Thin-film Silicon Resonators on Glass Substrate

2014 ◽  
Vol 87 ◽  
pp. 1418-1421
Author(s):  
J. Mouro ◽  
A. Gualdino ◽  
L. Teagno ◽  
V. Chu ◽  
J.P. Conde
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Glass Substrate ◽  
Thin Film Silicon ◽  
Silicon Resonators

Thin-film Photodiode with an a-Si:H/nc-Si:H Absorption Bilayer

2011 ◽  
Vol 1321 ◽  
Author(s):  
Y. Vygranenko ◽  
M. Vieira ◽  
A. Sazonov
Keyword(s):  
Thin Film ◽  
Leakage Current ◽  
Near Infrared ◽  
Spectral Response ◽  
Nanocrystalline Silicon ◽  
Depletion Region ◽  
Long Wavelength ◽  
Near Ultraviolet ◽  
High Bias ◽  
Bias Range

ABSTRACTWe report on the fabrication and characterization of n+-n-i-δi-p thin-film photodiodes with an active region comprising a hydrogenated nanocrystalline silicon (nc-Si:H) n-layer and a hydrogenated amorphous silicon (a-Si:H) i-layer. The combination of wide- and narrow-gap absorption layers enables the spectral response extending from the near-ultraviolet (NUV) to the near-infrared (NIR) region. Moreover, in the low-bias range, when only the i-layer is depleted, the leakage current is significantly lower than that in the conventional nc-Si:H n+-n-p+ photodiode deposited under the same deposition conditions. Device with the 900nm/400nm thick n-i-layers exhibits a reverse dark current density of 3 nA/cm2 at −1V. In the high-bias range, when the depletion region expands within the n-layer, the magnitude of the leakage current depends on electronic properties of nc-Si:H. The density of shallow and deep states, and diffusion length of holes in the n-layer have been estimated from the capacitance-voltage characteristics and from the bias dependence of the long-wavelength response, respectively. To improve the quantum efficiency in the NIR-region, we have also implemented a Cr / ZnO:Al back reflector. The observed long-wavelength spectral response is about twice as high as that for a reference photodiode without ZnO:Al layer. Results demonstrate the feasibility of the photodiode for low-level light detection in the NUV-to-NIR spectral range.

Effects of Reaction Conditions on MoS2 Thin Film Formation Synthesized by Chemical Vapor Deposition using Organic Precursor

MRS Advances ◽  
2016 ◽  
Vol 2 (29) ◽  
pp. 1533-1538 ◽  
Author(s):  
S. Ishihara ◽  
Y. Hibino ◽  
N. Sawamoto ◽  
T. Ohashi ◽  
K. Matsuura ◽  
...  
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Film Formation ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Axis Orientation

ABSTRACTMolybdenum disulfide (MoS2) thin films were fabricated by two-step chemical vapor deposition (CVD) using (t-C4H9)2S2 and the effects of temperature, gas flow rate, and atmosphere on the formation were investigated in order to achieve high-speed low-temperature MoS2 film formation. From the results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) investigations, it was confirmed that c-axis orientation of the pre-deposited Mo film has a significant involvement in the crystal orientation after the reaction low temperature sulfurization annealing and we successfully obtained 3 nm c-axis oriented MoS2 thin film. From the S/Mo ratios in the films, it was revealed that the sulfurization reaction proceeds faster with increase in the sulfurization temperature and the gas flow rate. Moreover, the sulfurization under the H2 atmosphere promotes decomposition reaction of (t-C4H9)2S2, which were confirmed by XPS and density functional theory (DFT) simulation.

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