scholarly journals Closed-Surface Multifunctional Antireflective Coating Made from SiO2 with TiO2 Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1367
Author(s):  
Zhiqiu Guo ◽  
Ze Zhu ◽  
Ya Liu ◽  
Changjun Wu ◽  
Hao Tu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Closed Surface ◽  
Chain Structure ◽  
High Photocatalytic Activity ◽  
Current Gain ◽  
Antireflective Coating ◽  
Reliability And Robustness

An SiO2-TiO2 closed-surface antireflective coating was fabricated by the one-dipping method. TiO2 nanoparticles were mixed with a nanocomposited silica sol, which was composed of acid-catalyzed nanosilica networks and silica hollow nanospheres (HNs). The microstructure of the sol-gel was characterized by transmission electron microscopy. The silica HNs were approximately 40–50 nm in diameter with a shell thickness of approximately 8–10 nm. The branched-chain structure resulting from acidic hydrolysis grew on these silica HNs, and TiO2 was distributed inside this network. The surface morphology of the coating was measured by field emission scanning electron microscopy and atomic force microscopy. After optimization, transmittance of up to 94.03% was obtained on photovoltaic (PV) glass with a single side coated by this antireflective coating, whose refractive index was around 1.30. The short-circuit current gain of PV module was around 2.14–2.32%, as shown by the current-voltage (IV) curve measurements and external quantum efficiency (EQE) tests. This thin film also exhibited high photocatalytic activity. Due to the lack of voids on its surface, the antireflective coating in this study possessed excellent long-term reliability and robustness in both high-moisture and high-temperature environments. Combined with its self-cleaning function, this antireflective coating has great potential to be implemented in windows and photovoltaic modules.

scholarly journals A New Study on the Temperature and Bias Dependence of the Kink Effects in S22 and h21 for the GaN HEMT Technology

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 353 ◽  
Author(s):  
Giovanni Crupi ◽  
Antonio Raffo ◽  
Valeria Vadalà ◽  
Giorgio Vannini ◽  
Alina Caddemi
Keyword(s):  
Short Circuit ◽  
Equivalent Circuit Model ◽  
Short Circuit Current ◽  
High Electron Mobility Transistor ◽  
Current Gain ◽  
Device Performance ◽  
High Electron ◽  
Gan Hemt ◽  
Temperature Conditions ◽  
Conventional Instrumentation

The aim of this feature article is to provide a deep insight into the origin of the kink effects affecting the output reflection coefficient (S22) and the short-circuit current-gain (h21) of solid-state electronic devices. To gain a clear and comprehensive understanding of how these anomalous phenomena impact device performance, the kink effects in S22 and h21 are thoroughly analyzed over a broad range of bias and temperature conditions. The analysis is accomplished using high-frequency scattering (S-) parameters measured on a gallium-nitride (GaN) high electron-mobility transistor (HEMT). The experiments show that the kink effects might become more or less severe depending on the bias and temperature conditions. By using a GaN HEMT equivalent-circuit model, the experimental results are analyzed and interpreted in terms of the circuit elements to investigate the origin of the kink effects and their dependence on the operating condition. This empirical analysis provides valuable information, simply achievable by conventional instrumentation, that can be used not only by GaN foundries to optimize the technology processes and, as a consequence, device performance, but also by designers that need to face out with the pronounced kink effects of this amazing technology.

Preparation of Cu2ZnSnS4 Treated with Post-Sulfurization in a Sulfur Vapor Atmosphere

2011 ◽  
Vol 239-242 ◽  
pp. 642-645 ◽  
Author(s):  
Min Yen Yeh ◽  
Dong Sing Wuu
Keyword(s):  
Spin Coating ◽  
Electrical Resistance ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Sulfur Vapor ◽  
Crystallinity Degree ◽  
Composition Ratios

Cu2ZnSnS4 (CZTS) prepared by sol-gel spin-coating deposition was treated with post-sulfurization in a sulfur vapor atmosphere. The crystallinity degree of the CZTS could be significantly improved through post-sulfurization treatment. Granular structures of the CZTS as synthesized at a temperature of over 240 °C and treated with post sulfurization were obtained. The composition ratios of the as-sulfurized CZTS were close to the composition stoichiometry of CZTS with an electrical resistance of ~ 1.7 Ω cm. An as-prepared CZTS based solar cell shows an open-circuit voltage of 300 mV, and a short-circuit current of 2.48 mA cm-2.

A Dynamic Response of a Module/Array Simulator Using I-V Magnifier Circuit of a PN Photo-Sensor

Solar Energy ◽  
2003 ◽  
Author(s):  
Hiroshi Nagayoshi
Keyword(s):  
Dynamic Response ◽  
Personal Computer ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Maximum Power ◽  
Current Gain ◽  
Led Driver ◽  
Photo Sensor ◽  
Driver Circuit ◽  
Basic Characteristics

Basic characteristics and dynamic response of a 30W module/array simulator using PV I-V magnifier circuit was studied. It was confirmed that each gain of voltage and current was independently adjustable using feedback control of current signal. Simulator circuit output power is controlled by LED irradiation light which works as an irradiation of sun light to real PV modules. Maximum power of the circuit depends on maximum power of the power amplifier used in the circuit. A photo-current of pn photo-sensor was some micro ampere hence the current gain of the simulator needed more than 50dB. The voltage gain was not more than 3dB because a multi junction pn photo-sensor was used. To control the simulator circuit by personal computer, an LED driver circuit was added. A fill factor was also easily changeable by change of shunt resistor connected with pn photo-sensor in parallel. A dynamic response of short circuit current was measured and confirmed that the circuit has enough response ability to apply the MPPT evaluation. A grand line of each module is isolated, hence any topology of connections is available. This circuit simplifies the control system and makes it easy to handle multi simulator units by one personal computer. This system is suitable for the evaluation of multi inverter system.

TEM Study of Rutile-Phase TiO2 Nanosheets

2013 ◽  
Vol 850-851 ◽  
pp. 156-159
Author(s):  
Xin Yan Wu ◽  
Wei Xiong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Rutile Phase ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process

TiO2 nanosheets have been successfully synthesized via a simple sol-gel process. These nanostructures were characterized by transmission electron microscopy (TEM) and x-ray energy dispersive spectrometer (EDS). The sheet-shaped single-crystalline nanostructures are pure rutile-phase structure, with landscape dimension of 10-45 nm. EDS investigation confirms that the TiO2 nanosheets are only composed of Ti and O, and the atomic ration of Ti and O is close to 1:2. High photocatalytic activity might be expected for those TiO2 nanosheets due to their large surface area.

scholarly journals Fabrication of Hybrid Polymer Solar Cells By Inverted Structure Based on P3HT:PCBM Active Layer

2017 ◽  
Vol 17 (1) ◽  
pp. 13
Author(s):  
Shobih Shobih ◽  
Rizky Abdillah ◽  
Erlyta Septa Rosa
Keyword(s):  
Solar Cells ◽  
Active Layer ◽  
Bulk Heterojunction ◽  
Polymer Solar Cells ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Hybrid Polymer

Hybrid polymer solar cell has privilege than its conventional structure, where it usually has structure of (ITO/PEDOT:PSS/Active Layer/Al). In humid environment the PEDOT:PSS will absorb water and hence can easily etch the ITO. Therefore it is necessary to use an alternative method to avoid this drawback and obtain more stable polymer solar cells, namely by using hybrid polymer solar cells structure with an inverted device architecture from the conventional, by reversing the nature of charge collection. In this paper we report the results of the fabrication of inverted bulk heterojunction polymer solar cells based on P3HT:PCBM as active layer, utilizing ZnO interlayer as buffer layer between the ITO and active layer with a stacked structure of ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag. The ZnO interlayer is formed through short route, i.e. by dissolving ZnO nanoparticles powder in chloroform-methanol solvent blend rather than by sol-gel process. Based on the measurement results on electrical characteristics of inverted polymer solar cells under 500 W/m2 illumination and AM 1.5 direct filter at room temperature, cell with annealing process of active layer at 110 °C for 10 minutes results in higher cell performance than without annealing, with an open-circuit voltage of 0.21 volt, a short-circuit current density of 1.33 mA/cm2 , a fill factor of 43.1%, and a power conversion efficiency of 0.22%. The low cell’s performance is caused by very rough surface of ZnO interlayer.

scholarly journals Performance Analysis of Mixed Natural Dye and Nanostructured Tio2 based DSSC

2020 ◽  
Vol 9 (7) ◽  
pp. 453-456
Keyword(s):  
Short Circuit ◽  
Electron Flow ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Natural Dye ◽  
Nanostructured Tio2 ◽  
Beet Root ◽  
The Stability ◽  
The Individual

The performance of the mixed natural dye based DSSC has been evaluated in this paper. The mixture of beet root, spinach and turmeric are used with nanostructured TiO2 are used for the fabrication of DSSC. TiO2 is synthesized by sol-gel technique and considered as semiconductor metal oxide (SMO) to act as photo anode here. Nano wire type of morphology of TiO2 is found from the FESEM image which exhibits unidirectional and uniform electron flow. The XRD study reveals anatase and rutile phases of TiO2 that ensure the stability of synthesized TiO2 . The mixed dye made of beet root, spinach and turmeric shows their congruent characteristics with the broad light absorption spectra, lower diffused reflectance spectra after anchoring with SMO and better I-V characteristics in comparison with the individual one. The mixed dye-based DSSC provides the open-circuit voltage of 0.755V, short circuit current of 2.05mA, voltage and current at maximum power equal to 0.51V and 1.7mA, respectively with the efficiency of 0.867 %, in comparison to the efficiency of the individual dyes 0.305%, 0.266% and 0.473% with beet root, spinach and turmeric, respectively.

scholarly journals A Study on the Effects of Selenization Temperature on the Properties of Na-Doped Cu2ZnSn(S,Se)4 Thin Film and Its Correlation with the Performance of Solar Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2434
Author(s):  
Zhanwu Wang ◽  
Dongyue Jiang ◽  
Fancong Zeng ◽  
Yingrui Sui
Keyword(s):  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Post Annealing ◽  
Different Temperatures ◽  
Selenization Temperature

In this study, we prepared Na-doped Cu2ZnSn(S,Se)4 [noted as (Na0.1Cu0.9)2ZnSn(S,Se)4] films on the Mo substrate using a simple and cheap sol–gel method together with the post-annealing technique. The effects of selenization temperature on the properties of Na-doped Cu2ZnSn(S,Se)4 were surveyed. The results indicated that some sulfur atoms in the films were substituted by selenium atoms by increasing the selenization temperature, and all films selenized at different temperatures had a kesterite structure. As the selenization temperature increased from 520 to 560 °C, the band gaps of the film can be tuned from 1.03 to 1 eV. The film with better morphology and opto-electrical properties can be obtained at an intermediate selenization temperature range (e.g., 540 °C), which had the lowest resistivity of 47.7 Ω cm, Hall mobility of 4.63 × 10−1 cm2/Vs, and carrier concentration of 2.93 × 1017 cm−3. Finally, the best power conversion efficiency (PCE) of 4.82% was achieved with an open circuit voltage (Voc) of 338 mV, a short circuit current density (Jsc) of 27.16 mA/cm2 and a fill factor (FF) of 52.59% when the selenization temperature was 540 °C.

scholarly journals Stability of High Band Gap P3HT : PCBM Organic Solar Cells Using TiOxInterfacial Layer

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Kurniawan Foe ◽  
Gon Namkoong ◽  
Matthew Samson ◽  
Enas M. Younes ◽  
Ilho Nam ◽  
...  
Keyword(s):  
Active Layer ◽  
Organic Solar Cells ◽  
Interfacial Layer ◽  
Short Circuit ◽  
Sol Gel ◽  
Acid Methyl Ester ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Photon Absorption

We fabricated a poly[3-hexylthiophene] (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) organic photovoltaic cells (OPCs) using TiOxinterfacial layer. We performed optimization processes for P3HT : PC61BM with the TiOxlayer. We found that a solution based TiOxlayer coated at a spin speed of 3000 rpm improved the photon absorption of the active layer. An optimized TiOxlayer was also used as the interfacial layer to investigate the stability of P3HT : PC61BM OPC. After 70 days of storage, we observed that the short-circuit current density (JSC) dropped by 16.2%, fill factor (FF) dropped by 10.6%, and power conversion efficiency (PCE) dropped approximately by 25%, while the open-circuit voltage (VOC) remained relatively stable. We found that a solution based TiOxlayer synthesized using a sol-gel chemistry method was very effective in protecting the active layer from degradation.

Sign in / Sign up

Export Citation Format

Share Document