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D V Lang

Publications and source records attributed to D V Lang.

6 recordsLinked to original sources
PubMed2004

Amorphouslike density of gap states in single-crystal pentacene.

We show that optical and electrical measurements on pentacene single crystals can be used to extract the density of states in the highest occupied molecular orbital-lowest unoccupied molecular orbital band gap. It is found that these highly purified crystals possess band tails broader than those typically observed in inorganic amorphous solids. Results on field-effect transistors fabricated from similar crystals imply that the gap state density is much larger within 5-10 nm of the gate dielectric. Thus, organic thin-film transistors for such applications as flexible displays might be significantly improved by reducing these defects.

Journal Article↗
PubMed2004

Bias-dependent generation and quenching of defects in pentacene.

We describe a defect generation phenomenon that is new to organic semiconductors. A defect in pentacene single crystals can be created by bias-stress and persists at room temperature for an hour in the dark but only seconds with 420 nm illumination. The defect gives rise to a hole trap at Ev+0.38 eV and causes metastable transport effects at room temperature. Creation and decay rates of the hole trap have a 0.67 eV activation energy with a small (10(8) s(-1)) prefactor, suggesting that atomic motion plays a key role in the generation and quenching process.

Journal Article↗
PubMed1983

Macroscopic bony deficiency of the tegmen tympani in adult temporal bones.

Bony deficiency of the tegmen tympani has been found in cases of fatal intracranial complications following air insufflation of the middle ear. This study set out to discover the incidence and appearance of such deficiencies. Seventy bones were examined and twenty per cent of them had tegmental deficiencies. There was no evidence of erosive disease in any of the bones. Reverse Politzerization following myringotomy has come to be regarded as a potentially dangerous procedure. It is also possible for infection to spread from the middle ear to the meninges, or for C.S.F. to leak into the middle ear from above.

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