scholarly journals Universal Strategy for Improving Perovskite Photodiode Performance: Interfacial Built‐In Electric Field Manipulated by Unintentional Doping

2021 ◽  
pp. 2101729
Author(s):  
Dan Wu ◽  
Wenhui Li ◽  
Haochen Liu ◽  
Xiangtian Xiao ◽  
Kanming Shi ◽  
...  
2008 ◽  
Vol 18 (04) ◽  
pp. 1013-1022 ◽  
Author(s):  
L. H. CHIEN ◽  
A. SERGEEV ◽  
N. VAGIDOV ◽  
V. MITIN

Employing Monte-Carlo simulations we investigate effects of an electric field on electron kinetics and transport in quantum-dot structures with potential barriers created around dots via intentional or unintentional doping. Results of our simulations demonstrate that the photoelectron capture is substantially enhanced in strong electric fields and this process has an exponential character. Detailed analysis shows that effects of the electric field on electron capture in the structures with barriers are not sensitive to the redistribution of electrons between valleys and these effects are not related to an increase of drift velocity. Most data find adequate explanation in the model of hot-electron transport in the potential relief of quantum dots. Electron kinetics controllable by potential barriers and an electric field may provide significant improvements in the photoconductive gain, detectivity, and responsivity of photodetectors.


2021 ◽  
Vol 8 (18) ◽  
pp. 2170120
Author(s):  
Dan Wu ◽  
Wenhui Li ◽  
Haochen Liu ◽  
Xiangtian Xiao ◽  
Kanming Shi ◽  
...  

Author(s):  
G. F. Rempfer

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.


Author(s):  
Patrick P. Camus

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).


1993 ◽  
Vol 3 (8) ◽  
pp. 1201-1225 ◽  
Author(s):  
G. N�ron de Surgy ◽  
J.-P. Chabrerie ◽  
O. Denoux ◽  
J.-E. Wesfreid

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