scholarly journals Effect of Multilayer Configuration on Spectral Response of Thin Film TiO2/NiO Heterojunction Photodetector

2021 ◽  
Author(s):  
Oday A. Hammadi
Keyword(s):  
Thin Film ◽  
Spectral Range ◽  
Spectral Response ◽  
Spectral Width ◽  
Single Peak ◽  
Response Intensity ◽  
Conventional Design ◽  
Multilayer Design ◽  
Heterojunction Device

Abstract In this work, a multilayer design for the TiO2/NiO heterojunction device is proposed. In this design, layers of TiO2 nanostructures are consecutively deposited on layers of NiO nanostructures deposited on ITO substrates. This design was compared to the conventional design of thin film TiO2/NiO heterojunction device by measuring the spectral response of both designs in the spectral range of 200–1200 nm. The proposed design showed increased response intensity by 14%, narrowing spectral width by 23% and single peak of response at 440nm.

Study on Light Induced Leakage Current Related to Amorphous Silicon TFT Design

2007 ◽  
Vol 124-126 ◽  
pp. 259-262
Author(s):  
Jae Hong Jeon ◽  
Kang Woong Lee
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Leakage Current ◽  
Thin Film Transistor ◽  
Silicon Layer ◽  
Gate Electrode ◽  
Silicon Thin Film ◽  
Pattern Design ◽  
Conventional Design ◽  
The One

We investigated the effect of amorphous silicon pattern design regarding to light induced leakage current in amorphous silicon thin film transistor. In addition to conventional design, where amorphous silicon layer is protruding outside the gate electrode, we designed and fabricated amorphous silicon thin film transistors in another two types of bottom gated structure. The one is that the amorphous silicon layer is located completely inside the gate electrode and the other is that the amorphous silicon layer is protruding outside the gate electrode but covered completely by the source and drain electrode. Measurement of the light induced leakage current caused by backlight revealed that the design where the amorphous silicon is located inside the gate electrode was the most effective however the last design was also effective in reducing the leakage current about one order lower than that of the conventional design.

Enhancement of Blue Spectral Response Intensity of PbS via Polyethylene Oxide-Adding for the Application to White LEDs

2011 ◽  
Vol 227 ◽  
pp. 39-42
Author(s):  
Samira Kaci ◽  
Aissa Keffous ◽  
Mohamed Trari ◽  
Brahim Mahmoudi ◽  
Hamid Menari
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Polyethylene Oxide ◽  
Spectral Response ◽  
Si Substrate ◽  
Surface Absorption ◽  
Response Intensity ◽  
White Leds ◽  
Cbd Method

In this work, we have employed chemical bath deposition (CBD) method to obtain nanocrystalline PbS thin films in the presence of polyethylene oxide (PEO). The spectral response of Au/PbS-pSi(100)/Al Schottky photodiodes at different PEO amount were studied. The response exhibits a combined effect of photogeneration in the heterojunction (HJ) Si side and PbS. Spectral response were observed progressively at shorter wavelength due to the surface absorption. The peak centered at 410 nm properly corresponds to photo-exited holes being injected from PbS to the Si substrate. The intensity of the peak of R(λ) increases with PEO amount, this increasing was attributed to the decreasing of band gap (Eg).

scholarly journals Wide-Range Enhancement of Spectral Response by Highly Conductive and Transparentμc-SiOx:H Doped Layers inμc-Si:H and a-Si:H/μc-Si:H Thin-Film Solar Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Pei-Ling Chen ◽  
Po-Wei Chen ◽  
Min-Wen Hsiao ◽  
Cheng-Hang Hsu ◽  
Chuang-Chuang Tsai
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Spectral Response ◽  
Wavelength Region ◽  
Thin Film Solar Cells ◽  
Window Layer ◽  
Efficiency Gain ◽  
Silicon Thin Film ◽  
Single Junction ◽  
Wide Range

The enhancement of optical absorption of silicon thin-film solar cells by the p- and n-typeμc-SiOx:H as doped and functional layers was presented. The effects of deposition conditions and oxygen content on optical, electrical, and structural properties ofμc-SiOx:H films were also discussed. Regarding the dopedμc-SiOx:H films, the wide optical band gap (E04) of 2.33 eV while maintaining a high conductivity of 0.2 S/cm could be obtained with oxygen incorporation of 20 at.%. Compared to the conventionalμc-Si:H(p) as window layer inμc-Si:H single-junction solar cells, the application ofμc-SiOx:H(p) increased theVOCand led to a significant enhancement in the short-wavelength spectral response. Meanwhile, the employment ofμc-SiOx:H(n) instead of conventional ITO as back reflecting layer (BRL) enhanced the external quantum efficiency (EQE) ofμc-Si:H single-junction cell in the long-wavelength region, leading to a relative efficiency gain of 10%. Compared to the reference cell, the optimized a-Si:H/μc-Si:H tandem cell by applying p- and n-typeμc-SiOx:H films achieved aVOCof 1.37 V,JSCof 10.55 mA/cm2, FF of 73.67%, and efficiency of 10.51%, which was a relative enhancement of 16%.

Validation of thin film TiO2 optical constants by reflectometry and ellipsometry in the VUV spectral range

2019 ◽  
Vol 30 (4) ◽  
pp. 045201 ◽  
Author(s):  
Alexander Gottwald ◽  
Karl Wiese ◽  
Thomas Siefke ◽  
Mathias Richter
Keyword(s):  
Thin Film ◽  
Spectral Range ◽  
Optical Constants

Subwavelength Periodic Structures Design and its Role in Photon Control of Thin Film Solar Cells

NANO ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. 2050139
Author(s):  
Zhiye Wang ◽  
Xiangqian Shen ◽  
Shuying Wang ◽  
Hua Zhou ◽  
Peihua Wangyang ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Periodic Structures ◽  
Spectral Response ◽  
Incident Light ◽  
Optical Loss ◽  
Thin Film Solar Cells ◽  
Photoelectric Conversion Efficiency ◽  
Optimized Design ◽  
Photoelectric Conversion

A subtle modification of the device surface is able to reduce optical loss and to further achieve high photoelectric conversion efficiency for thin film solar cells. This work shows the manipulation properties of subwavelength periodic structures on incident light at air/glass surface. In order to explore the mechanisms of optical loss, the spectral response and energy distribution of light are investigated by using rigorous coupled wave analysis and finite difference time domain methods. Calculation results show that the diffraction scattering and gradient refraction index play a significant role for better photon harvesting. With an optimized design of [Formula: see text][Formula: see text]nm, [Formula: see text], and hemispherical shape structure, obvious improvement in transmittance, external quantum efficiency and photo-generated current is achieved. The photoelectric conversion efficiencies of amorphous silicon thin film cells with an absorbing layer thickness of 400[Formula: see text]nm is 8.04%, improved by 5.9% compared with the flat cell of equivalent size.

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.

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