A new method is developed to calculate the photoabsorption and photoyield of small spheres. Numerical results are presented for the case of free-electron spheres for photon energies below the plasmon energies. It is found that the excitation of electron-hole pairs due to the presence of the surface results in enhancements in photoabsorption and photoyields that are typically 10-${10}^2$ relative to the classical results, which only include the excitation of transverse modes. Furthermore, enhancements of the order 10-${10}^2$ are found in the photoyield of small spheres relative to plane surfaces. These results are consistent with recent experimental results on a number of non-free-electron materials.

• Received 4 December 1981

DOI:https://doi.org/10.1103/PhysRevB.26.3047