A Study of the Photovoltaic effect of A Semiconductor Grain Boundary by A Scanning Laser Beam

1985 ◽  
Vol 54 ◽  
Author(s):  
Jerng-Sik Song ◽  
Edward S. Yang
Keyword(s):  
Grain Boundary ◽  
Laser Beam ◽  
Open Circuit Voltage ◽  
Photovoltaic Effect ◽  
Thermionic Emission ◽  
Open Circuit ◽  
Scanning Laser ◽  
Trap Energy ◽  
Recombination Velocity ◽  
Recombination Current

ABSTRACTExperimental observation of the photovoltaic effect of a semiconductor grain boundary with a scanning laser beam is analyzed assuming a single trap energy level. The photo-current is calculated from the recombination velocity and the concentration of minority carriers at a grain boundary which was derived from the continuity equation. Open circuit voltage across a sample is obtained from equating this recombination current to compensating thermionic emission current. Using recombination velocity and diffusion length as variables, tha calculated open circuit voltage is compared with experimental data.

Enhanced efficacy of defect passivation and charge extraction for efficient perovskite photovoltaics with a small open circuit voltage loss

2019 ◽  
Vol 7 (15) ◽  
pp. 9025-9033 ◽  
Author(s):  
Jin-Feng Liao ◽  
Wu-Qiang Wu ◽  
Jun-Xing Zhong ◽  
Yong Jiang ◽  
Lianzhou Wang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Open Circuit Voltage ◽  
Power Conversion ◽  
Charge Recombination ◽  
Open Circuit ◽  
Polymeric Semiconductor ◽  
Voltage Loss ◽  
Defect Passivation

A multifunctional 2D polymeric semiconductor was incorporated to provide surprisingly robust efficacy in grain boundary functionalization and defect passivation of perovskite, which suppresses charge recombination and thus affording an illustrious photovoltage of 1.16 V and power conversion efficiency of 21.1%.

scholarly journals Numerical Simulation Analysis of Ag Crystallite Effects on Interface of Front Metal and Silicon in the PERC Solar Cell

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Myeong Sang Jeong ◽  
Yonghwan Lee ◽  
Ka-Hyun Kim ◽  
Sungjin Choi ◽  
Min Gu Kang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Surface Recombination ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Metal Interface ◽  
Ag Crystallites ◽  
Recombination Velocity

In the fabrication of crystalline silicon solar cells, the contact properties between the front metal electrode and silicon are one of the most important parameters for achieving high-efficiency, as it is an integral element in the formation of solar cell electrodes. This entails an increase in the surface recombination velocity and a drop in the open-circuit voltage of the solar cell; hence, controlling the recombination velocity at the metal-silicon interface becomes a critical factor in the process. In this study, the distribution of Ag crystallites formed on the silicon-metal interface, the surface recombination velocity in the silicon-metal interface and the resulting changes in the performance of the Passivated Emitter and Rear Contact (PERC) solar cells were analyzed by controlling the firing temperature. The Ag crystallite distribution gradually increased corresponding to a firing temperature increase from 850 ∘C to 950 ∘C. The surface recombination velocity at the silicon-metal interface increased from 353 to 599 cm/s and the open-circuit voltage of the PERC solar cell decreased from 659.7 to 647 mV. Technology Computer-Aided Design (TCAD) simulation was used for detailed analysis on the effect of the surface recombination velocity at the silicon-metal interface on the PERC solar cell performance. Simulations showed that the increase in the distribution of Ag crystallites and surface recombination velocity at the silicon-metal interface played an important role in the decrease of open-circuit voltage of the PERC solar cell at temperatures of 850–900 ∘C, whereas the damage caused by the emitter over fire was determined as the main cause of the voltage drop at 950 ∘C. These results are expected to serve as a steppingstone for further research on improvement in the silicon-metal interface properties of silicon-based solar cells and investigation on high-efficiency solar cells.

High Open-Circuit Voltage in Silicon Heterojunction Solar Cells

2007 ◽  
Vol 989 ◽  
Author(s):  
Qi Wang ◽  
Matt R. Page ◽  
Eugene Iwancizko ◽  
Yueqin Xu ◽  
Lorenzo Roybal ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Open Circuit Voltage ◽  
Surface Recombination ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Back Surface ◽  
Float Zone ◽  
Double Heterojunction ◽  
Type C ◽  
Recombination Velocity

AbstractHigh open-circuit voltage (Voc) silicon heterojunction (SHJ) solar cells are fabricated in double-heterojunction a-Si:H/c-Si/a-Si:H structures using low temperature (<225°C) hydrogenated amorphous silicon (a-Si:H) contacts deposited by hot-wire chemical vapor deposition (HWCVD). On p-type c-Si float-zone wafers, we used an amorphous n/i contact to the top surface and an i/p contact to the back surface to obtain a Voc of 667 mV in a 1 cm2 cell with an efficiency of 18.2%. This is the best reported p-type SHJ voltage. In our labs, it improves over the 652 mV cell obtained with a front amorphous n/i heterojunction emitter and a high-temperature alloyed Al back-surface-field contact. On n-type c-Si float-zone wafers, we used an a Si:H (p/i) front emitter and an a-Si:H (i/n) back contact to achieve a Voc of 691 mV on 1 cm2 cell. Though not as high as the 730 mV reported by Sanyo on n-wafers, this is the highest reported Voc for SHJ c-Si cells processed by the HWCVD technique. We found that effective c-Si surface cleaning and a double-heterojunction are keys to obtaining high Voc. Transmission electron microscopy reveals that high Voc cells require an abrupt interface from c-Si to a-Si:H. If the transition from the base wafer to the a-Si:H incorporates either microcrystalline or epitaxial Si at c Si interface, a low Voc will result. Lifetime measurement shows that the back-surface-recombination velocity (BSRV) can be reduced to ~15 cm/s through a-Si:H passivation. Amorphous silicon heterojunction layers on crystalline wafers thus combine low-surface recombination velocity with excellent carrier extraction.

Photovoltaic Effect in Single Layer 1H-Pyrazolo[3,4-b]quinoline and 1H-Pyrazolo[3,4-b]quioxaline/Poly(3-Decylthiophene) Polymer Cells

2009 ◽  
Vol 64 (9-10) ◽  
pp. 632-638 ◽  
Author(s):  
Ewa Gondek ◽  
Ivan V. Kityk ◽  
Andrzej Danel
Keyword(s):  
Polymer Matrix ◽  
Ground State ◽  
Open Circuit Voltage ◽  
Dipole Moments ◽  
Photovoltaic Effect ◽  
Single Layer ◽  
Open Circuit ◽  
The State ◽  
Polymer Matrices ◽  
Ground State Dipole Moments

We have explored photovoltaic (PV) reponse for the pyrazoloquinoline and pyrazoloquinoxaline dyes incorporated into the poly(3-decylthiophene) (PDT) polymer matrices. The photovoltaic response correlates generally with the enhancement of the state dipole moments. Generally we have shown that enhanced state dipole moments lead to an increase of the open circuit voltage. The surrounded polymer matrix of the polythiophene enhances the ground state dipole moments and its relative changes are decreased with the increase of the particular state dipole moments. An appearance of the three-phenyl backside groups substantially diminishes the effect.

scholarly journals Near Infrared Lateral Photovoltaic Effect in LaTiO3Films

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Wujun Jin ◽  
Shasha Zhang ◽  
Hao Ni ◽  
Wenfeng Xiang ◽  
Jianfeng Xi ◽  
...  
Keyword(s):  
Laser Beam ◽  
Near Infrared ◽  
Photovoltaic Effect ◽  
Open Circuit ◽  
Bias Current ◽  
Sensitive Detection ◽  
Photoelectronic Device ◽  
Position Sensitive ◽  
Open Circuit Photovoltage

We have reported on the lateral photovoltaic effect of LaTiO3films epitaxially grown on (100) SrTiO3substrates. Under illumination of continuous 1064 nm laser beam on the LaTiO3film through SrTiO3substrate, the open-circuit photovoltage depended linearly on the illuminated position. The photosensitivity can be modified by bias current. These results indicated that the LaTiO3films give rise to a potentially photoelectronic device for near infrared position-sensitive detection.

Measurement of Grain Boundary Parameters by Laser-Spot Photoconductivity

1982 ◽  
Vol 17 ◽  
Author(s):  
E. Poon ◽  
H.L. Evans ◽  
W. Hwang ◽  
R.M. Osgood ◽  
E.S. Yang
Keyword(s):  
Steady State ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Laser Beam ◽  
Cross Section ◽  
Capture Cross Section ◽  
Capture Cross ◽  
Transient Signals ◽  
Trap Energy ◽  
Interface Charge

ABSTRACTAn experimental technique has been developed to study the electrical properties of semiconductor grain boundaries (GBs) by a focused laser beam. The laser beam is trained on a GB while the photoconductivity of the sample is measured. Both the steady-state and transient signals are recorded as functions of temperature. From these data, we obtain well-defined GB parameters, including the barrier height, interface charge density, trap energy and thermal capture cross-section. This technique allows us to examine localized regions of individual GBs in a semiconductor with multiple grains.

scholarly journals Synthesis and Photovoltaic Effect of Electron-Withdrawing Units for Low Band Gap Conjugated Polymers Bearing Bi(thienylenevinylene) Side Chains

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1461 ◽  
Author(s):  
Jianfeng Li ◽  
Yufei Wang ◽  
Ningning Wang ◽  
Zezhou Liang ◽  
Xu Wang ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Open Circuit Voltage ◽  
Photovoltaic Effect ◽  
Photovoltaic Performance ◽  
Hole Mobility ◽  
Open Circuit ◽  
Photovoltaic Devices ◽  
Good Thermal Stability ◽  
Highest Occupied Molecular Orbital ◽  
Donor Acceptor

A novel (E)-5-(2-(5-alkylthiothiophen-2-yl)vinyl)thien-2-yl (TVT)-comprising benzo[1,2-b:4,5-b’]dithiophene (BDT) derivative (BDT-TVT) was designed and synthetized to compose two donor-acceptor (D-A) typed copolymers (PBDT-TVT-ID and PBDT-TVT-DTNT) with the electron-withdrawing unit isoindigo (ID) and naphtho[1,2-c:5,6-c′]bis[1,2,5]thiadiazole (NT), respectively. PBDT-TVT-ID and PBDT-TVT-DTNT showed good thermal stability (360 °C), an absorption spectrum from 300 nm to 760 nm and a relatively low lying energy level of Highest Occupied Molecular Orbital (EHOMO) (−5.36 to –5.45 eV), which could obtain a large open-circuit voltage (Voc) from photovoltaic devices with PBDT-TVT-ID or PBDT-TVT-DTNT. The photovoltaic devices with ITO/PFN/polymers: PC71BM/MoO3/Ag structure were assembled and exhibited a good photovoltaic performance with a power conversion efficiency (PCE) of 4.09% (PBDT-TVT-ID) and 5.44% (PBDT-TVT-DTNT), respectively. The best PCE of a PBDT-TVT-DTNT/PC71BM-based device mainly originated from its wider absorption, higher hole mobility and favorable photoactive layer morphology.

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