arXiv subjects

Mingguo Liu

Publications and source records attributed to Mingguo Liu.

2 recordsLinked to original sources

arXiv2016

Half-filled intermediate bands Si material formed by energetically metastable interstitial sulfur atom

Hyperdoped metastable sulfur atoms endow crystalline silicon with a strong sub-bandgap light absorption. In order to explore such metastable states, we develop a new high-throughput first-principles calculation method to search for all of the energetically metastable states for an interstitial sulfur atom inside crystalline silicon. Finally, we obtain sixty-three metastable interstitial states and they can be classified into ten types. Interestingly, twenty-eight (44% in total) of lower-energy metastable states can produce a well-isolated and half-filled intermediate band (IB) inside silicon forbidden gap, which makes sulfur hyperdoped silicon to be a desirable material for IB solar cells.

cond-mat.mtrl-sci↗

arXiv2009

Reversal of current blockade through multiple trap correlations

Current noise in electronic devices usually arises from uncorrelated charging events, with individual transitions resolved only at low temperatures. However, in 1-D nanotube-based transistors, we have observed random telegraph signal (RTS) with unprecedented signal-to-noise ratio at room temperature. In addition, we find evidence for cooperative multi-trap interactions that give rise to a characteristically terminated RTS: current blockade induced by one trap is found to fully reverse through electrostatic `passivation' by another. Our observations are well described by a robust quantum transport model that demonstrates how strong correlation and fast varying potentials can resolve energetically proximal states along a 1-D channel.

cond-mat.mtrl-sci↗