Depletion Region

2021 ◽  
Author(s):  
Mathieu Hautefeuille ◽  
Juan Hernández-Cordero
Keyword(s):  
Depletion Region

scholarly journals Effects of CsSnxPb1−xI3 Quantum Dots as Interfacial Layer on Photovoltaic Performance of Carbon-Based Perovskite Solar Cells

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Chi Zhang ◽  
Zhiyuan He ◽  
Xuanhui Luo ◽  
Rangwei Meng ◽  
Mengwei Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Photovoltaic Performance ◽  
Perovskite Solar Cells ◽  
Photogenerated Electron ◽  
Depletion Region ◽  
Band Alignment ◽  
Back Surface ◽  
The One ◽  
Carbon Based

AbstractIn this work, inorganic tin-doped perovskite quantum dots (PQDs) are incorporated into carbon-based perovskite solar cells (PSCs) to improve their photovoltaic performance. On the one hand, by controlling the content of Sn2+ doping, the energy level of the tin-doped PQDs can be adjusted, to realize optimized band alignment and enhanced separation of photogenerated electron–hole pairs. On the other hand, the incorporation of tin-doped PQDs provided with a relatively high acceptor concentration due to the self-p-type doping effect is able to reduce the width of the depletion region near the back surface of the perovskite, thereby enhancing the hole extraction. Particularly, after the addition of CsSn0.2Pb0.8I3 quantum dots (QDs), improvement of the power conversion efficiency (PCE) from 12.80 to 14.22% can be obtained, in comparison with the pristine device. Moreover, the experimental results are analyzed through the simulation of the one-dimensional perovskite/tin-doped PQDs heterojunction.

Investigation of Surface Passivation in InAs/GaSb Strained-Layer-Superlattices Using Picosecond Excitation Correlation Measurement and Variable-Area Diode Array Surface Recombination Velocity Measurement

2005 ◽  
Vol 891 ◽  
Author(s):  
Zhimei Zhu ◽  
Elena Plis ◽  
Abdenour Amtout ◽  
Pallab Bhattacharya ◽  
Sanjay Krishna
Keyword(s):  
Infrared Detectors ◽  
Surface Passivation ◽  
Surface Recombination ◽  
Surface States ◽  
Depletion Region ◽  
Surface Recombination Velocity ◽  
Diode Array ◽  
Ammonium Sulfide ◽  
Picosecond Excitation ◽  
Recombination Velocity

ABSTRACTThe effect of ammonium sulfide passivation on InAs/GaSb superlattice infrared detectors was investigated using two complementary techniques, namely, picosecond excitation correlation (PEC) measurement and variable-area diode array (VADA) surface recombination velocity (SRV) measurement. PEC measurements were conducted on etched InAs/GaSb superlattice mesas, which were passivated in aqueous ammonium sulfide solutions of various strengths for several durations. The PEC signal's decay time constant (DTC) is proportional to carrier lifetimes. At 77 K the PEC signal's DTC of the as-grown InAs/GaSb superlattice sample was 2.0 ns, while that of the unpassivated etched sample was reduced to 1.2 ns by the surface states at the mesa sidewalls. The most effective ammonium sulfide passivation process increased the PEC signal's DTC to 10.4 ns. However it is difficult to isolate surface recombination from other processes that contribute to the lifetime using the PEC data, therefore a VADA SRV measurement was undertaken to determine the effect of passivation on surface recombination. The obtained SRV in the depletion region of the InAs/GaSb superlattice and GaSb junction was 1.1×106 cm/s for the unpassivated sample and 4.6×105 cm/s for the passivated sample. At 77 K the highest R0A value measured in our passivated devices was 2540 W cm2 versus 0.22 W cm2 for the unpassivated diodes. The results of the lifetime, the SRV and the R0A measurements indicate that ammonium sulfide passivation will improve the performance of InAs/GaSb superlattice infrared detectors.

Research on the Type of Electrical Contact at Metal-Insulator Interface

2011 ◽  
Vol 383-390 ◽  
pp. 5154-5157
Author(s):  
Qian Peng ◽  
Li Ren Zhou
Keyword(s):  
Electrical Contact ◽  
Depletion Region ◽  
Energy Band Structure ◽  
Metal Insulator ◽  
Band Bending ◽  
Whole Process ◽  
Insulator Interface ◽  
Metal Insulator Metal ◽  
Electrode Metal ◽  
Nor Band

This paper takes metal-insulator-metal system as example and investigates the main types of electrical contact through the view of energy band structure, to analyze the whole process of the transition from ohm contact to barrier contact. Ohm contact, which promotes charges injection from electrode (metal) to insulator, can be used as storage of charge carrier, which is body limited; it can also be regarded as a type of contact that forms an accumulation layer extending from the interface to the interior of the insulator. Whereas, barrier contact is a type of contact which forms a depletion region extending from the interface to the interior of insulator. As for this type of contact, electron injection from metal tends to the state of saturation. The characteristic of neutral contact is that there is no space charge in the insulator, nor band bending, which means the boundary of conduction band and valence band up to the interface is flat.

Carrier Concentrations and Drift Currents in the Depletion Region of a p–n Junction

2003 ◽  
Vol 10 (04) ◽  
pp. 649-660
Author(s):  
D. K. Mak
Keyword(s):  
Solid State ◽  
Applied Voltage ◽  
Local Minimum ◽  
Local Maximum ◽  
Depletion Region ◽  
Electron Drift ◽  
Electron Carrier ◽  
Quantitative Explanation ◽  
State Device ◽  
Solid State Device

It has always been stated in electronics, semiconductor and solid state device textbooks that the hole drift and electron drift currents in the depletion region of a p–n junction are constant and independent of applied voltage (biasing). However, the explanations given are qualitative and unclear. We extrapolate the existing analytic theory of a p–n junction to give a quantitative explanation of why the currents are constant. We have also shown that the carrier concentrations in the depletion region, as depicted in some of the textbooks, are incorrect, and need to be revised. Our calculations further demonstrate that in reverse biasing, both hole and electron carrier concentrations each experience a local maximum and a local minimum, indicating that their diffusion currents change directions twice within the depletion region.

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