Excitons in large-gap insulators: Solid neon

Excitons at the fundamental edge ($17 1$) are determined in the effective-mass approximation, modified to include the spin-orbit splitting of the valence band and the electron-hole exchange interaction, the latter being estimated from the excitation spectrum of gaseous neon. Full correspondence of the atomic transitions (2p)⁶→2p⁵ms (m≥3) and n≥1 valence excitons in solid neon has been established. Relative intensities of the partners in the nth doublets (n≥1) are determined explaining the presence of only one exciton series in solid neon, unlike other rare-gas solids. Further structure above the threshold has been interpreted in terms of the joint density of states.