Sapan Agarwal and Eli Yablonovitch

EECS Department, University of California, Berkeley

Technical Report No. UCB/EECS-2013-245

December 31, 2013

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-245.pdf

While science has good knowledge of semiconductor bandgaps, there is not much information regarding the steepness of the band-edges. We find that a plot of absolute conductance, I/V versus voltage, V, in an Esaki diode or a backward diode will reveal a best limit for the band tails, defined by the tunneling joint density of states of the two band-edges. This joint density of states will give information about the prospective subthreshold swing voltage that could be expected in a tunneling field effect transistor. To date, published I-V characteristics indicate that the joint band-tail density of states is not steep enough to achieve less than 60mV/decade. Heavy doping inhomogeneity, among other inhomogeneities, result in a gradual density of states extending into the band gap. The steepest measured tunnel diodes have had a tunneling joint density of states greater than 90mV/decade.

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BibTeX citation:

@techreport{Agarwal:EECS-2013-245,
    Author= {Agarwal, Sapan and Yablonovitch, Eli},
    Title= {Band-Edge Steepness Obtained from Esaki/Backward Diode Current-Voltage Characteristics},
    Year= {2013},
    Month= {Dec},
    Url= {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-245.html},
    Number= {UCB/EECS-2013-245},
    Abstract= {While science has good knowledge of semiconductor bandgaps, there is not much information regarding the steepness of the band-edges. We find that a plot of absolute conductance, I/V versus voltage, V, in an Esaki diode or a backward diode will reveal a best limit for the band tails, defined by the tunneling joint density of states of the two band-edges. This joint density of states will give information about the prospective subthreshold swing voltage that could be expected in a tunneling field effect transistor. To date, published I-V characteristics indicate that the joint band-tail density of states is not steep enough to achieve less than 60mV/decade. Heavy doping inhomogeneity, among other inhomogeneities, result in a gradual density of states extending into the band gap. The steepest measured tunnel diodes have had a tunneling joint density of states greater than 90mV/decade.},
}

EndNote citation:

%0 Report
%A Agarwal, Sapan 
%A Yablonovitch, Eli 
%T Band-Edge Steepness Obtained from Esaki/Backward Diode Current-Voltage Characteristics
%I EECS Department, University of California, Berkeley
%D 2013
%8 December 31
%@ UCB/EECS-2013-245
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-245.html
%F Agarwal:EECS-2013-245