Picosecond Photomodulation Study of Nanocrystalline Hydrogenated Silicon

1989 ◽  
Vol 164 ◽  
Author(s):  
M. Wraback ◽  
Lingrong Chen ◽  
J. Tauc ◽  
Z. Vardeny
Keyword(s):  
Light Intensity ◽  
Amorphous Phase ◽  
Temporal Resolution ◽  
Time Domain ◽  
Hydrogenated Silicon ◽  
High Illumination ◽  
Recombination Processes

AbstractWe have extended our photomodulation studies of nc-Si:H to the picosecond time domain. We measured the decays of photoinduced reflectivity with 100fs temporal resolution as a function of light intensity. Comparison with the data obtained on a-Si:H and c-Si indicates that ultrafast trapping and recombination processes are mainly the properties of the amorphous phase. It has also been observed that nc-Si:H is unstable under high illumination.

Direct observation of electron emission and recombination processes by time domain measurements of charge pumping current

2015 ◽  
Vol 106 (4) ◽  
pp. 041603 ◽  
Author(s):  
Masahiro Hori ◽  
Tokinobu Watanabe ◽  
Toshiaki Tsuchiya ◽  
Yukinori Ono
Keyword(s):  
Direct Observation ◽  
Time Domain ◽  
Electron Emission ◽  
Charge Pumping ◽  
Recombination Processes

scholarly journals Give Me a Few Hours: Exploring Short Timescales in Rubin Observatory Cadence Simulations

2022 ◽  
Vol 258 (1) ◽  
pp. 13
Author(s):  
Eric C. Bellm ◽  
Colin J. Burke ◽  
Michael W. Coughlin ◽  
Igor Andreoni ◽  
Claudia M. Raiteri ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Time Domain ◽  
Temporal Evolution ◽  
Transient Behavior ◽  
Wide Range ◽  
Pair Separation ◽  
Astrophysical Phenomena

Abstract The limiting temporal resolution of a time-domain survey in detecting transient behavior is set by the time between observations of the same sky area. We analyze the distribution of visit separations for a range of Vera C. Rubin Observatory cadence simulations. Simulations from families v1.5–v1.7.1 are strongly peaked at the 22 minute visit pair separation and provide effectively no constraint on temporal evolution within the night. This choice will necessarily prevent Rubin from discovering a wide range of astrophysical phenomena in time to trigger rapid follow-up. We present a science-agnostic metric to supplement detailed simulations of fast-evolving transients and variables and suggest potential approaches for improving the range of timescales explored.

A Propos de la Création de Photoporteurs à Partir d'Excitons dans CdS

1971 ◽  
Vol 49 (14) ◽  
pp. 1967-1970 ◽  
Author(s):  
A. Coret ◽  
H. L. Malm
Keyword(s):  
Light Intensity ◽  
Photoconductivity Spectrum ◽  
Free Carriers ◽  
Recombination Processes ◽  
The Creation

According to the variation of the photoconductivity spectrum of CdS with light intensity it appears that excitons do not play a role in the recombination processes of photocarriers. Excitons first dissociate and give free carriers. The existence of maxima of photocurrent is related to the creation of photocarriers near the surface.

scholarly journals Prospects on Time-Domain Diffuse Optical Tomography Based on Time-Correlated Single Photon Counting for Small Animal Imaging

2016 ◽  
Vol 2016 ◽  
pp. 1-23 ◽  
Author(s):  
Yves Bérubé-Lauzière ◽  
Matteo Crotti ◽  
Simon Boucher ◽  
Seyedrohollah Ettehadi ◽  
Julien Pichette ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Time Domain ◽  
Single Photon ◽  
Optical Tomography ◽  
Photon Counting ◽  
Diffuse Optical Tomography ◽  
Small Animal ◽  
Acquisition Time ◽  
High Temporal Resolution ◽  
Single Photon Counting

This paper discusses instrumentation based on multiview parallel high temporal resolution (<50 ps) time-domain (TD) measurements for diffuse optical tomography (DOT) and a prospective view on the steps to undertake as regards such instrumentation to make TD-DOT a viable technology for small animal molecular imaging. TD measurements provide information-richest data, and we briefly review the interaction of light with biological tissues to provide an understanding of this. This data richness is yet to be exploited to its full potential to increase the spatial resolution of DOT imaging and to allow probing, via the fluorescence lifetime, tissue biochemical parameters, and processes that are otherwise not accessible in fluorescence DOT. TD data acquisition time is, however, the main factor that currently compromises the viability of TD-DOT. Current high temporal resolution TD-DOT scanners simply do not integrate sufficient detection channels. Based on our past experience in developing TD-DOT instrumentation, we review and discuss promising technologies to overcome this difficulty. These are single photon avalanche diode (SPAD) detectors and fully parallel highly integrated electronics for time-correlated single photon counting (TCSPC). We present experimental results obtained with such technologies demonstrating the feasibility of next-generation multiview TD-DOT therewith.

Light-intensity and temperature dependence of trap-dangling bond recombination in hydrogenated microcrystalline silicon

2002 ◽  
Vol 715 ◽  
Author(s):  
Christoph Boehme ◽  
Klaus Lips
Keyword(s):  
Electron Spin Resonance ◽  
Magnetic Resonance ◽  
Light Intensity ◽  
Quantitative Study ◽  
Time Domain ◽  
Dangling Bond ◽  
Microcrystalline Silicon ◽  
Spin Resonance ◽  
Electrically Detected Magnetic Resonance ◽  
Tunneling Recombination

AbstractA quantitative study of the trap-dangling bond tunneling recombination in hydrogenated microcrystalline silicon (μc-Si:H) is presented. The transition coefficients were measured at various light exposures and temperatures between T = 10 K and T = 140 K using time-domain measurements of spin-dependent recombination (TSR). TSR is a new characterization method related to electrically detected magnetic resonance (EDMR). It combines the advantages of pulsed electron spin resonance with that of EDMR. In contrast to previous models, the experimental results can only be interpreted if the interaction between the spins of the trap and the dangling bonds as well as triplet recombination is considered.

Light Intensity Exponents as Sensitive Tools for the Detection of Impurities in a-Si:H

2000 ◽  
Vol 609 ◽  
Author(s):  
L. F. Fonseca ◽  
S.Z. Weisz ◽  
P. Alpuim ◽  
V. Chu ◽  
J.P. Conde ◽  
...  
Keyword(s):  
Light Intensity ◽  
Temperature Dependence ◽  
Computer Simulations ◽  
Dominant Factor ◽  
State Distribution ◽  
Capture Coefficient ◽  
Yield Information ◽  
Recombination Processes ◽  
Minority Carriers ◽  
Forbidden Gap

ABSTRACTWe have shown recently that the temperature dependence of the phototransport properties can yield information regarding the state distribution in the forbidden gap of semiconductors. Of these properties the light intensity exponents of both, the majority carriers, γe, and the minority carriers, γh, were found to be very sensitive to the details of this distribution. In particular, noting that sub 1/2 values of the exponents are very unusual we have studied their origin in some a-Si:H materials. Finding experimentally such sub 1/2 values of γh and running computer simulations of the recombination processes in a-Si:H led us to the conclusion that these low values are due to acceptor-like centers which have a relatively high capture coefficient for the holes. We attribute these centers to the unintentional oxygen doping in a-Si:H. We will show that the oxygen presence, usually ignored in the discussions of the phototransport properties of a-Si:H, appears to be, in many cases, the dominant factor in the properties of “intrinsic” a-Si:H.

Time-domain and lock-in rate-window photocarrier radiometric measurements of recombination processes in silicon

2005 ◽  
Vol 98 (12) ◽  
pp. 123518 ◽  
Author(s):  
Andreas Mandelis ◽  
Micha Pawlak ◽  
Chinhua Wang ◽  
Isabel Delgadillo-Holtfort ◽  
Josef Pelzl
Keyword(s):  
Time Domain ◽  
Radiometric Measurements ◽  
Recombination Processes ◽  
Lock In ◽  
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