Photon-induced deactivations of multiple traps in CH3NH3PbI3 perovskite films by different photon energies

2021 ◽  
Author(s):  
Asmida Herawati ◽  
Hui-Ching Lin ◽  
Shun-Hsiang Chan ◽  
Ming-Chung Wu ◽  
Tsong-Shin Lim ◽  
...  
Keyword(s):  
Conduction Band ◽  
Energy Levels ◽  
Conduction Band Minimum ◽  
The Other ◽  
Electron Traps

Two types of electron traps were identified in MAPbI3 perovskite; one can be deactivated by 633 nm and 405 nm illuminations, whereas the other one only by 405 nm illumination. The energy levels of both traps were beneath the conduction band minimum.

DLTS Study of Pd-H Complexes in Si

2012 ◽  
Vol 725 ◽  
pp. 213-216
Author(s):  
Sunao Abe ◽  
Ryuichi Goura ◽  
Koichi Shimoe ◽  
Yoichi Kamiura ◽  
Yoshifumi Yamashita ◽  
...  
Keyword(s):  
Conduction Band ◽  
Energy Levels ◽  
Annealing Behavior ◽  
Electron Traps

We have observed five electron traps with energy levels at 0.16, 0.30, 0.40, 0.53 and 0.67 eV below the conduction band in Pd and H doped Si by DLTS technique. Successive annealing at 373 K and 473 K for 30 min respectively caused two levels at Ec-0.16 eV and Ec-0.67 eV to disappear and simultaneously a new level to emerge at Ec-0.19 eV. From such annealing behavior and the comparison of the energy levels observed in the present study with those in the literature, we assign them to various Pd and H related defects as follows, Pd-H2: Ec-0.16 eV and Ec-0.67 eV, Pd acceptor: Ec-0.19 eV, Pd-H3: Ec-0.30 eV, Pd-H1: Ec-0.40 eV.

Conduction band minimum of CdTe

1964 ◽  
Vol 25 (4) ◽  
pp. 443-447 ◽  
Author(s):  
W.G. Spitzer ◽  
C.A. Mead
Keyword(s):  
Conduction Band ◽  
Conduction Band Minimum

Passivation and Depassivation of Interface Traps at the SiO2/4H-SiC Interface by Potassium Ions

2012 ◽  
Vol 717-720 ◽  
pp. 761-764 ◽  
Author(s):  
Pétur Gordon Hermannsson ◽  
Einar Ö. Sveinbjörnsson
Keyword(s):  
Thermal Stability ◽  
Conduction Band ◽  
Energy Levels ◽  
Sample Surface ◽  
Conduction Band Edge ◽  
Potassium Ions ◽  
Interface Traps ◽  
Bias Stress ◽  
Dry Oxidation ◽  
Thermal Stability Of

We investigate the passivation of interface traps by method of oxidizing Si-face 4H-SiC in the presence of potassium as well as examining the thermal stability of this passivation process. It is observed that this type of dry oxidation leads to a strong passivation of interface traps at the SiO2/4H-SiC interface with energy levels near the SiC conduction band edge. Furthermore, it is observed that if potassium ions residing at the SiO2/SiC interface are moved towards the sample surface by exposing them to ultraviolet light (UV) under an applied depletion bias stress at high temperatures the interface traps become electrically active again and are evidently depassivated. These findings are in line with recently a published model of the effect of sodium on such interface states

The Defect Structure of BaTiO3 Thin Films

1993 ◽  
Vol 310 ◽  
Author(s):  
L.A. Wills ◽  
B.W. Wessels
Keyword(s):  
Thin Films ◽  
Cross Section ◽  
Defect Structure ◽  
Oxygen Vacancies ◽  
Vacuum Annealing ◽  
Deep Level ◽  
Energy Levels ◽  
The Other ◽  
Optical Cross Section ◽  
Impurity Defects

AbstractThe defect structure of BaTiO3 thin films grown on (100) Si was examined using transient photocapacitance spectroscopy. The concentration, optical cross section and associated energy levels of both native and impurity defects in as-grown and annealed BaTiO3 films were evaluated. Deep level defects withpeak energies of Ev+1.8, Ev+2.4, Ev+2.7, Ev+3.0-3.1 and Ev+3.2-3.3 eV were observed in the as-grown films. Upon vacuum annealing, the concentration of the traps at Ev+3.0 and Ev+3.2 eV increased while the concentration of the traps at Ev+ 1.8 and Ev+2.4 eV decreased. The levels at Ev+3.0-3.1 and Ev+3.2-3.3 eV are attributed to oxygen vacancies. The other levels are tentatively ascribed to Fe and Fe related defects.

scholarly journals Doped TiO2: the effect of doping elements on photocatalytic activity

2020 ◽  
Vol 1 (5) ◽  
pp. 1193-1201 ◽  
Author(s):  
Anna Khlyustova ◽  
Nikolay Sirotkin ◽  
Tatiana Kusova ◽  
Anton Kraev ◽  
Valery Titov ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Conduction Band ◽  
Energy Levels ◽  
Doped Tio2 ◽  
New Energy ◽  
Effect Of Doping

Doping of TiO2 with various elements increases its photocatalytic activity due to the formation of new energy levels near the conduction band.

scholarly journals Energy Level Engineering of Charge Selective Contact and Halide Perovskite by Modulating Band Offset: Mechanistic Insights

2020 ◽  
Author(s):  
Yassine Raoui ◽  
Hamid Ez-Zahraouy ◽  
Samrana Kazim ◽  
Shahzada Ahmad
Keyword(s):  
Solar Cells ◽  
Energy Level ◽  
Conduction Band ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Conduction Band Minimum ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Band Offset ◽  
Interfacial Recombination

<p>Mixed cation and anion based perovskites solar cells (FAPbI<sub>3</sub>)<sub>0.85</sub>(MAPbBr<sub>3</sub>)<sub>0.15</sub> gave enhanced stability under outdoor conditions, however, it yielded limited power conversion efficiency when SnO<sub>2</sub> and Spiro-OMeTAD were employed as electron and hole transport layer (ETL/HTL). The inevitable interfacial recombination of charge carriers at ETL/perovskite and perovskite/HTL interface diminished the efficiency in planar (n-i-p) perovskite solar cells. Employing computational approach for uni-dimensional device simulator, the effect of band offset on charge recombination at both interfaces were investigated. We noted that it acquired cliff structure when the conduction band minimum of the ETL is lower than that of the perovskite, and thus maximizes interfacial recombination. However, if the conduction band minimum of ETL is higher than perovskite, i.e. spike structure is formed, which improve the performance of solar cell up to an optimum value of conduction band offset allowing to reach performance of 25.21%, with an open circuit voltage (<i>V</i><sub>oc</sub>) of 1231 mV, a current density <i>J</i><sub>sc</sub> of 24.57 mA/cm<sup>2</sup> and a fill factor of 83.28%. Additionally, we found that beyond the optimum offset value, large spike structure could decrease the performance. With an optimized, energy level of Spiro-OMeTAD and the thickness of mixed-perovskite layer performance of 26.56 % can be attained. Our results demonstrate a detailed understanding about the energy level tuning between the charge selective layers and perovskite and furthermore how the improvement in PV performance can be achieved by adjusting the energy level offset.</p>

scholarly journals The principal magnetic susceptibilities of neodymium sulphate octahydrate at low temperatures

1939 ◽  
Vol 170 (941) ◽  
pp. 266-271 ◽  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Energy Levels ◽  
Constant Factor ◽  
The Other ◽  
Crystalline Field ◽  
Cubic Symmetry ◽  
The Subject ◽  
The Difference ◽  
The One

The magnetic and other related properties of neodymium sulphate have been the subject of numerous investigations in recent years, but there is still a remarkable conflict of evidence on all the essential points. The two available determinations of the susceptibility of the powdered salt at low temperatures, those of Gorter and de Haas (1931) from 290 to 14° K and of Selwood (1933) from 343 to 83° K both fit the expression X ( T + 45) = constant over the range of temperature common to both, but the constants are not the same and the susceptibilities at room temperature differ by 11%. The fact that the two sets of results can be converted the one into the other by multiplying throughout by a constant factor suggested that the difference in the observed susceptibilities was due to some error of calibration. It could, however, also be due to the different purity of the samples examined though the explanation of the occurrence of the constant factor is then by no means obvious. From their analysis of the absorption spectrum of crystals of neodymium sulphate octahydrate Spedding and others (1937) conclude that the crystalline field around the Nd+++ ion is predominantly cubic in character since they find three energy levels at 0, 77 and 260 cm. -1 .* Calculations of the susceptibility from these levels reproduce Selwood’s value at room temperature but give no agreement with the observations-at other temperatures. On the other hand, Penney and Schlapp (1932) have shown that Gorter and de Haas’s results fit well on the curve calculated for a crystalline field of cubic symmetry and such a strength that the resultant three levels lie at 0, 238 and 834 cm. -1 , an overall spacing almost three times as great as Spedding’s.

Conduction band minimum of CdTe

1964 ◽  
Vol 2 (2) ◽  
pp. 62
Author(s):  
W.G. Spitzer ◽  
C.A. Mead
Keyword(s):  
Conduction Band ◽  
Conduction Band Minimum

scholarly journals The effect on rats of practical diets containing different protein and energy levels

1983 ◽  
Vol 17 (4) ◽  
pp. 330-335 ◽  
Author(s):  
D. J. Ford ◽  
R. J. Ward
Keyword(s):  
Energy Level ◽  
Lower Energy ◽  
Energy Levels ◽  
Amino Acid Content ◽  
Bodyweight Gain ◽  
The Other ◽  
Food Utilization ◽  
Fat Deposits ◽  
Consequent Increase ◽  
Different Levels

Rats of 3 strains were fed diets of natural ingredients in 4 different laboratories. The diets contained different levels of protein and energy within ranges comparable to those found in existing laboratory diets. Energy level over the range examined appeared to exert greatest influence on bodyweight gain, but had no effect on food intake. The diet with the highest amino acid content was consumed in smaller amounts than the other diets. Food utilization was less efficient in the lower energy diets. Fat deposition was reduced in animals fed the lowest energy diet. It is concluded that energy level of the diet exerts an effect on the rate of bodyweight gain in rats, but that for longer-term studies a reduced energy level may be beneficial by leading to smaller fat deposits with consequent increase in longevity.

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