DMC Study of the Optoelectronic Properties of Diamondoids

Abstract

ABSTRACTWe have performed density-functional theory (DFT) and quantum Monte Carlo (QMC) calculations of the optoelectronic properties of hydrogen-terminated carbon nanoparticles (diamondoids). Both the QMC and DFT results show that quantum confinement effects disappear in diamondoids larger than 1 nm in diameter, which have optical gaps below that of bulk diamond. Furthermore, our QMC calculations predict a negative electron affinity for diamondoids up to 1 nm in diameter. Both these properties result from the delocalized nature of the lowest unoccupied molecular orbital.