Oxygen effects on the interfacial electronic structure of titanyl phthalocyanine film: p-Type doping, band bending and Fermi level alignment

2006 ◽  
Vol 325 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Toshio Nishi ◽  
Kaname Kanai ◽  
Yukio Ouchi ◽  
Martin R. Willis ◽  
Kazuhiko Seki
Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 547
Author(s):  
Zengguang Tang ◽  
Liujiang Zhang ◽  
Zhenhuang Su ◽  
Zhen Wang ◽  
Li Chen ◽  
...  

In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.


2006 ◽  
Vol 455 (1) ◽  
pp. 227-233 ◽  
Author(s):  
Toshio Nishi ◽  
Kaname Kanai ◽  
Yukio Ouchi ◽  
Martin R. Willis ◽  
Kazuhiko Seki

1992 ◽  
Vol 260 ◽  
Author(s):  
Changyoung Kim ◽  
Paul L. King ◽  
Piero Pianetta

ABSTRACTA photoelectron microscope operating with a retarding field analyzer has been used to exploit core level energy shifts due to band bending in order to directly image Fermi level variations on n- and p-type cleaved GaAs(110) surfaces. Fermi level maps resolved to better than 10 um indicate lateral variations in the surface Fermi level which are often quite abrupt. In agreement with earlier, lower resolution work [1], Fermi level topography is found to be highly correlated with surface roughness as characterized by SEM, optical microscope and stylus profi lometer. The largest defect derived pinnings encountered to date resut in the Fermi level lying 0.5 eV above the VBM for both n- and p-type GaAs. Low coverage In evaporations have the. effect of reducing Fermi level contrast as Fermi levels in formerly unpinned regions move into the gap.


1988 ◽  
Vol 100 ◽  
Author(s):  
L. E. Mosley ◽  
M. A. Paesler ◽  
P. D. Richard

ABSTRACTIt has been observed that doping produces an enhancement in the recrystallization growth rate of silicon made amorphous by ionimplantation. This enhancement has been attributed to a shift of the Fermi level with doping. Evidence supporting this is based on the compensating effect of implantation of n- and p-type dopants together. We have previously proposed a model of the recrystallization growth process based on the diffusion of dangling bonds. We suggested that the rate enhancement is due to band bending at the amorphous-crystalline interface produced by doping. We have calculated the change in activation energy for the recrystallization growth velocity for a number of doping concentrations as a function of temperature. The major contribution to the apparent lowering of the activation energy with doping in an Arrhenius plot of the growth velocity versus I/kT is due to the temperature dependence of the Fermi level. Experimental data are compared with the calculated results. In addition differences in the measured growth rates in thermal and laser annealed samples are discussed, with primary emphasis on the lack of a change in the activation energy with doping in the laser annealed case.


2018 ◽  
Vol 20 (18) ◽  
pp. 12939-12947 ◽  
Author(s):  
Andrey A. Kistanov ◽  
Yongqing Cai ◽  
Kun Zhou ◽  
Sergey V. Dmitriev ◽  
Yong-Wei Zhang

A proper adoption of the n- or p-type dopants allows for the modulation of the work function, the Fermi level pinning, the band bending, and the photo-adsorbing efficiency near the InSe surface/interface.


2012 ◽  
Vol 194 ◽  
pp. 266-271 ◽  
Author(s):  
Janusz Toboła ◽  
Piotr Zwolenski ◽  
Stanisław Kaprzyk

Electronic structure calculations of doped Mg2(Si-Ge) semiconductors were performed by the charge self-consistent Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) in order to search for p-type impurities. It was predicted that Li and Na (located on Mg site) as well as B, Ru, Mo and W (located on Si site) are expected to behave as hole donors in Mg2(Si-Ge). Using the calculated density of states in doped Mg2Si in the vicinity of the Fermi level, the linear term of thermopower was also estimated from the simplified Mott's formula. The RT Seebeck coefficient may range from 120μV/K (Li) to almost 300μV/K (Ru) at the 1% content of doped impurities.


2021 ◽  
Vol 118 (5) ◽  
pp. 052101
Author(s):  
Youjung Kim ◽  
Hyeongmin Cho ◽  
Kookrin Char

2014 ◽  
Vol 895 ◽  
pp. 420-423 ◽  
Author(s):  
Sathya Sheela Subramanian ◽  
Baskaran Natesan

Structural optimization, magnetic ground state and electronic structure calculations of tetragonal PbMnO3have been carried out using local density approximation (LDA) implementations of density functional theory (DFT). Structural optimizations were done on tetragonal P4mm (non-centrosymmetric) and P4/mmm (centrosymmetric) structures using experimental lattice parameters and our results indicate that P4mm is more stable than P4/mmm. In order to determine the stable magnetic ground state of PbMnO3, total energies for different magnetic configurations such as nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM) were computed for both P4mm and P4/mmm structures. The total energy results reveal that the FM non-centrosymmetric structure is found to be the most stable magnetic ground state. The electronic band structure, density of states (DOS) and the electron localization function (ELF) were calculated for the stable FM structure. ELF revealed the distorted non-centrosymmetric structure. The band structure and DOS for the majority spins of FM PbMnO3showed no band gap at the Fermi level. However, a gap opens up at the Fermi level in minority spin channel suggesting that it could be a half-metal and a potential spintronic candidate.


2009 ◽  
Vol 79-82 ◽  
pp. 1253-1256 ◽  
Author(s):  
Li Guan ◽  
Qiang Li ◽  
Xu Li ◽  
Jian Xin Guo ◽  
Bo Geng ◽  
...  

In the present paper, the lattice structure, band structure and density of state of pure and P-doped ZnO are calculated by first-principle method based on density functional theory. By analyzing the Mulliken charge overlap population and bond length, it is found that the bond of P-Zn is longer and stronger than O-Zn bond for PO-ZnO. But for PZn-ZnO, the O-P bond becomes shorter and more powerful than O-Zn bond. Also, weak O-O bonds are formed in this case. Our results show that the final total energy of PO-ZnO is lower than PZn-ZnO. The lattice structure of PO-ZnO is more stability than PZn-ZnO. For PO-ZnO, The Fermi level moves into the valence band, which expresses that the holes appear on the top of valence band and thus the PO-ZnO exhibits p-type conductivity. For PZn-ZnO, the Fermi level moves up to the conductor band and the total density of states shifts to the lower energy region, thus PZn-ZnO shows the n-type conductivity.


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