Transient photoconductivity measurements of carrier lifetimes in an InAs∕In0.15Ga0.85As dots-in-a-well detector

2007 ◽  
Vol 90 (10) ◽  
pp. 103519 ◽  
Author(s):  
Mary R. Matthews ◽  
Robert J. Steed ◽  
Mark D. Frogley ◽  
Chris C. Phillips ◽  
Ram S. Attaluri ◽  
...  
1989 ◽  
Vol 161 ◽  
Author(s):  
W. O. Doggett ◽  
Michael W. Thelander ◽  
J. F. Schetzina

ABSTRACTA system has been developed for accurately measuring lifetimes for photo-induced excess current carriers in semiconductors using the transient photoconductivity decay method. The specifications of state-of-the-art equipment, considerations peculiar to the capture of fast transient pulses, and sophisticated statistical data analysis techniques are discussed. Experimental results are presented to demonstrate the capability of the system (a) to measure lifetimes in the 40-ns - 75-µs range for temperatures varying from 77K to 300K with 10% accuracy for single lifetime decays and 30% accuracy for individual effective lifetimes in a multi-component decay, and (b) to use a 300-ns lifetime photoconductor as a detector to measure nanosecond-time-scale structure of laser pulses. The predominant excess carrier lifetimes of HgCdTe samples grown at NCSU by photoassisted molecular beam epitaxy (PAMBE) ranged from 46 ns at 300K to 341 ns at 77K. CdTe samples and CdMnTe-CdTe superlattices exhibited a multi-component decay with the two longest components having effective lifetimes of 26 µs and 4 µs for CdTe and 75 µs and 10 µs for CdMnTe-CdTe. These values were relatively insensitive to temperature variation.


1996 ◽  
Vol 441 ◽  
Author(s):  
S. P. Ahrenkiel ◽  
R. K. Ahrenkiel ◽  
D. J. Arent

AbstractWe examine the influences of spontaneous atomic ordering and the associated subvariant domain structure on the transient photoconductivity in epitaxial Ga0.47In0.53As films grown by MOCVD on InP 2°-<110>. Ultra-high frequency photoconductivity decay is used to measure carrier lifetimes in ordered and disordered material following excitation with a YAG laser. Ordered material shows an extended lifetime of 18–186 gis that decreases with incident power. Strongly ordered material showed two CuPt-B subvariants in TEM diffraction patterns and images. Ordering in the first 0.5 μm of growth consists of a fine, interwoven structure with the subvariants closely associated. The subvariants then segregate into imperfectly ordered columnar superdomains that form a mosaic in the film plane with numerous order/order interfaces. In addition, order/disorder interfaces form within and adjacent to the partially ordered superdomains. We attribute the extended transient photoconductivity lifetime in ordered samples to trapping effects that result from the subvariant domain structure.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1803
Author(s):  
Zhen Zheng ◽  
Junyang An ◽  
Ruiling Gong ◽  
Yuheng Zeng ◽  
Jichun Ye ◽  
...  

In this work, we report the same trends for the contact potential difference measured by Kelvin probe force microscopy and the effective carrier lifetime on crystalline silicon (c-Si) wafers passivated by AlOx layers of different thicknesses and submitted to annealing under various conditions. The changes in contact potential difference values and in the effective carrier lifetimes of the wafers are discussed in view of structural changes of the c-Si/SiO2/AlOx interface thanks to high resolution transmission electron microscopy. Indeed, we observed the presence of a crystalline silicon oxide interfacial layer in as-deposited (200 °C) AlOx, and a phase transformation from crystalline to amorphous silicon oxide when they were annealed in vacuum at 300 °C.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rui He ◽  
Tingting Chen ◽  
Zhipeng Xuan ◽  
Tianzhen Guo ◽  
Jincheng Luo ◽  
...  

Abstract Wide-bandgap (wide-E g , ∼1.7 eV or higher) perovskite solar cells (PSCs) have attracted extensive attention due to the great potential of fabricating high-performance perovskite-based tandem solar cells via combining with low-bandgap absorbers, which is considered promising to exceed the Shockley–Queisser efficiency limit. However, inverted wide-E g PSCs with a minimized open-circuit voltage (V oc) loss, which are more suitable to prepare all-perovskite tandem devices, are still lacking study. Here, we report a strategy of adding 1,3,5-tris (bromomethyl) benzene (TBB) into wide-E g perovskite absorber to passivate the perovskite film, leading to an enhanced average V oc. Incorporation of TBB prolongs carrier lifetimes in wide-E g perovskite due to reduction of defects in perovskites and makes a better energy level matching between perovskite absorber and electron transport layer. As a result, we achieve the power conversion efficiency of 17.12% for our inverted TBB-doped PSC with an enhanced V oc of 1.19 V, compared with that (16.14%) for the control one (1.14 V).


Nano Letters ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 1952-1958 ◽  
Author(s):  
Chih-Shan Tan ◽  
Yicheng Zhao ◽  
Rong-Hao Guo ◽  
Wei-Tsung Chuang ◽  
Lih-Juann Chen ◽  
...  

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