scholarly journals Dual nanocomposite carrier transport layers enhance the efficiency of planar perovskite photovoltaics

RSC Advances ◽  
2018 ◽  
Vol 8 (23) ◽  
pp. 12526-12534 ◽  
Author(s):  
Hsi-Kuei Lin ◽  
Jia-Xing Li ◽  
Hao-Cheng Wang ◽  
Yu-Wei Su ◽  
Kaung-Hsiung Wu ◽  
...  
Keyword(s):  
Active Layer ◽  
Carrier Transport ◽  
Short Circuit ◽  
Power Conversion ◽  
Short Circuit Current ◽  
Photovoltaic Devices ◽  
Current Densities ◽  
Effective Transfer ◽  
Conversion Efficiencies

In photovoltaic devices, more effective transfer of dissociated electrons and holes from the active layer to the respective electrodes will result in higher fill factors and short-circuit current densities and, thus, enhanced power conversion efficiencies (PCEs).

scholarly journals Fabrication of TiO2/Dye-Sensitized Solar Cells (DSCs) Using Dye Extracts and Their Mixture as Photosensitizers

2019 ◽  
pp. 1-9
Author(s):  
T. O. Ahmed ◽  
P. O. Akusu ◽  
N. Alu ◽  
A. L. Aluko
Keyword(s):  
Power Conversion Efficiency ◽  
Absorption Maximum ◽  
Short Circuit ◽  
Power Conversion ◽  
Visible Spectrum ◽  
Short Circuit Current ◽  
Hibiscus Sabdariffa ◽  
Tio2 Films ◽  
Delonix Regia ◽  
Current Densities

In this work we have reported an investigation on Hibiscus sabdariffa and Delonix regia dye extracts and their mixture as natural sensitizers for TiO2/DSCs. A shift in the absorption maximum toward the lower energy of the ultraviolet-visible spectrum was observed for the dye mixture and a shift in the absorption maximum towards the higher energy of the ultraviolet-visible spectrum was observed for the dye extracts. The optical band gaps obtained at the point where the absorption spectra showed strong cut offs range from 1.79eV to 2.40eV. Also, we have used TiO2 thin films of thickness 5.2μm and the Light Harvesting Efficiencies (LHE) of the dye extracts and the dye mixture adsorbed onto TiO2 surface were close to unity. The average diameter of the TiO2 films obtained from SEM is in the range of 25-40nm reflecting that the TiO2 films are transparent and suitable for DSC application. The XRD pattern revealed the TiO2 films to be of anatase form and the structure type is tetragonal with 3.53217Å as the d-spacing for the most prominent peak, 2θ=25.2139° (ICDD data file: 01-075-8897). Three (3) DSCs each of 0.52 cm2 active area were assembled and subjected to current-voltage characterization using a standard overhead Veeco viewpoint solar simulator equipped with AM 1.5 filter to give a solar radiation of 1000 W/m2 and coupled to Keithley source meter (model 4200SCS). The photoelectrochemical performance of the fabricated DSCs showed open-circuit voltages (Voc) varied from 0.42 to 0.53 V, the short-circuit current densities (Jsc) ranged from 0.10mAcm-2 to 0.90mAcm-2 and the fill factors (FF) varied from 12 to 38%. The best overall solar power conversion efficiency of 0.13% was obtained, under AM 1.5 irradiation and a maximum short circuit current density of 0.90mAcm-2. Nevertheless, pure Hibiscus sabdariffa and Delonix regia dye extracts proved to be rather poor sensitizers as can be seen by the low spectra absorption at lower energies with current densities of 0.17mAcm-2 and 0.10mAcm-2 respectively. The solar power conversion efficiencies for Hibiscus sabdariffa and Delonix regia dye extracts were 0.01% and 0.02% respectively. In our earlier studies, we highlighted an established fact that raw natural dye mixtures exhibit better performance than pure dye extracts. Thus, the power conversion efficiency of 0.13% observed for the dye mixture sensitized TiO2/DSC corresponds to an increment in the neighborhood of 85% to 92% over the pure dye extracts sensitized TiO2/DSCs.

A NEW APPROACH TO IDEAL AlGaAs MQW SOLAR CELLS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 778-781 ◽  
Author(s):  
J. C. RIMADA ◽  
L. HERNÁNDEZ
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Quantum Wells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Depletion Region ◽  
Open Circuit ◽  
Current Densities ◽  
Conversion Efficiencies ◽  
Open Circuit Voltages

A theoretical model has been developed which shows that the insertion of multi-quantum wells into the depletion region of a p-i(MQW)-n Al x Ga 1-x As solar cell can significantly enhance the conversion efficiencies. Open-circuit voltages, short-circuit current densities, I-V curves and conversion efficiencies have been calculated as functions of the well and barrier band gaps, width and depth of the wells, number of wells in the intrinsic region and the recombination rate in the interfaces. Particular emphasis is placed on calculation of absorption of the Al x Ga 1-x As quantum wells. These results are matched with p-i-n solar cells which are identical in all respects except that they do not have quantum wells. We demonstrated that for determined values of the studied parameters the conversion efficiencies of the quantum well solar cell is higher to corresponding cell without quantum wells.

scholarly journals Delineating the enhanced efficiency of carbon nanomaterials including the hierarchical architecture of the photoanode of dye-sensitized solar cells

2020 ◽  
Vol 1 (8) ◽  
pp. 2964-2970
Author(s):  
Venkatesan Srinivasan ◽  
Jagadeeswari Sivanadanam ◽  
Kothandaraman Ramanujam ◽  
Mariadoss Asha Jhonsi
Keyword(s):  
Current Density ◽  
Carbon Nanomaterials ◽  
Short Circuit ◽  
Power Conversion ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Hierarchical Architecture ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

The inclusion of CNMs together with TiO2 enhanced the short circuit current density by 31% and power conversion efficiency (PCE) by 46% compared to the CNM-free DSSCs.

Solar Cell Contacts Using Nano-Sized Dispersions

1999 ◽  
Vol 581 ◽  
Author(s):  
Doug Schulz ◽  
R. Ribelin ◽  
X. Wu ◽  
K.M. Jones ◽  
R.J. Matson ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spray Deposition ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Cdte Layer ◽  
Open Circuit ◽  
Alloy Formation ◽  
Current Densities ◽  
P Type ◽  
Open Circuit Voltages

ABSTRACTNano-sized dispersions have been employed as precursor inks for the spray deposition of contacts to both Si and CdTe materials. In the case of Si, nano-sized Al particles (nano-Al) were dispersed and spray deposited onto p-type Si. Annealing above the eutectic temperature causes alloy formation yielding a p+ layer with p ∼ 10−4 Ω•cm. For CdTe, nano-sized Te particles (nano-Te) were dispersed and sprayed onto CdTe/CdS/SnO2/glass heterostructures. Contact to the CdTe layer occurred during a 30 min anneal in He (T = 215 to 255 °C). These solar cells were finished by spin-coating the Te layer with Ag paint and subsequently annealing in air (100 °C / 1 h). This approach produces solar cells with open circuit voltages (Voc) from 720 to 800 mV, short circuit current densities (Jsc) from 18 to 20 mA/cm2 and efficiencies up to 10.3%. The performance of these cells was similar to those produced using the standard NREL contact.

scholarly journals Toward Current Matching in Tandem Dye-Sensitized Solar Cells

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2936
Author(s):  
Junfeng Wei ◽  
Zhipeng Shao ◽  
Bin Pan ◽  
Shuanghong Chen ◽  
Linhua Hu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Dye Sensitized ◽  
Current Matching ◽  
Current Densities ◽  
Experimental Findings ◽  
Photovoltaic Technologies ◽  
Sensitized Solar Cells

The tandem pn-type dye-sensitized solar cells (pn-DSCs) have received much attention in the field of photovoltaic technologies because of their great potential to overcome the Shockley-Queisser efficiency limitation that applies to single junction photovoltaic devices. However, factors governing the short-circuit current densities (Jsc) of pn-DSC remain unclear. It is typically believed that Jsc of the pn-DSC is limited to the highest one that the two independent photoelectrodes can achieve. In this paper, however, we found that the available Jsc of pn-DSC is always determined by the larger Jsc that the photoanode can achieve but not by the smaller one in the photocathode. Such experimental findings were verified by a simplified series circuit model, which shows that a breakdown will occur on the photocathode when the photocurrent goes considerably beyond its threshold voltage, thus leading to an abrupt increase in Jsc of the circuit. The simulation results also suggest that a higher photoconversion efficiency of the pn-DSCs can be only achieved when an almost equivalent photocurrent is achieved for the two photoelectrodes.

scholarly journals Characteristics of A Hybrid Detector Combined with A Perovskite Active Layer for Indirect X-ray Detection

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6872
Author(s):  
Hailiang Liu ◽  
Jehoon Lee ◽  
Jungwon Kang
Keyword(s):  
Surface Roughness ◽  
Active Layer ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Lower Surface ◽  
Short Circuit Current Density ◽  
Charge Carriers ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Hybrid Detector

In this study, we investigated the characteristics of an organic-inorganic hybrid indirect-type X-ray detector with a CH3NH3PbI3 (MAPbI3) perovskite active layer. A layer with a thickness of 192 nm annealed at 100 °C showed higher absorption, higher crystallinity, and lower surface roughness than did perovskite layers made under different conditions. In the indirect X-ray detector, a scintillator coupled with the detector to convert X-ray photons to visible photons, and the converted photons were absorbed by the active layer to generate charge carriers. The detector with the optimized MAPbI3 (192 nm thick and 100 °C annealing condition) active layer was coupled with a CsI(Tl) scintillator which consisted of 400 μm thick CsI and 0.5 mm thick Al, and achieved the highest sensitivity, i.e., 2.84 mA/Gy·cm2. In addition, the highest short-circuit current density (JSC), i.e., 18.78 mA/cm2, and the highest mobility, i.e., 2.83 × 10−4 cm2/V·s, were obtained from the same detector without the CsI(Tl) scintillator.

Study on the Small Molecule Organic Solar Cells with Anode Buffer Layer

2012 ◽  
Vol 550-553 ◽  
pp. 476-479
Author(s):  
Ai Fen Wang
Keyword(s):  
Buffer Layer ◽  
Active Layer ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Photovoltaic Cell ◽  
Open Circuit ◽  
Experimental Result ◽  
Anode Buffer Layer ◽  
Buffer Material

The three photovoltaic cells with two different anode buffer layer on the basis of Pentacene/C60 as active layer was fabicated, the effect and mechanism of anode buffer layer on performance of organic photovoltaic cell are explored. The experimental result shows transition metal oxide inserted between organic active layer and ITO could increase short circuit current and open-circuit voltage,power conversion efficiency is increased to 107%,so it is effective anode buffer material.

The Influence of the Magnetic Field on the Current-Voltage Characteristics of CuPc Nanowires

2019 ◽  
Vol 970 ◽  
pp. 75-81
Author(s):  
Alexey Zavgorodniy ◽  
Aitbek Aimukhanov ◽  
Assylbek Zeinidenov ◽  
Galina Vavilova
Keyword(s):  
Magnetic Field ◽  
Carrier Transport ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Photosensitive Cell ◽  
Positively Charged

The role of spin states in the process of charge carrier transport in copper phthalocyanine (CuPc) nanowires has been established. According to the data obtained, CuPc nanowires are in the η-phase. The current-voltage characteristics (IVC) of a photosensitive cell based on CuPc nanowires in a magnetic field are investigated. As a result of experiments, it was found that applying an external magnetic field, the spins of two positively charged polarons are oriented in one direction. The channel of formation of the bipolaron is blocked. As a result, a decrease in the short-circuit current of the photosensitive cell is observed by more than 61%.

High face-on ratio isoindigo copolymers with extended nano-fibrillar networks in fullerene-based thick (>300 nm) photovoltaics achieving a high efficiency of 10.7%

2019 ◽  
Vol 7 (37) ◽  
pp. 21309-21320 ◽  
Author(s):  
Song-Fu Liao ◽  
Chun-Fu Lu ◽  
Adane Desta Fenta ◽  
Chin-Ti Chen ◽  
Chi-Yang Chao ◽  
...  
Keyword(s):  
Active Layer ◽  
Current Density ◽  
High Efficiency ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Fibrillar Network

In addition to the thick active layer (>300 nm), the extended nano-fibrillar network and a high face-on ratio of isoindigo copolymers in the nano-fibrillar network raise the short-circuit current density up to 22 mA cm−2 and efficiency near 10.7%.

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