Comment on "Shallow donor states near a semiconductor-insulator-metal interface"

TL;DR

This paper critically evaluates recent variational calculations of shallow donor energy states near a semiconductor-insulator-metal interface, confirming the accuracy of earlier methods over newer approaches.

Contribution

It clarifies the validity of MacMillen and Landman's theoretical approach, countering recent claims of improved accuracy by Hao et al.

Findings

MacMillen and Landman's method yields accurate energy values.

Hao et al.'s variational approach does not outperform earlier methods.

Previous estimates of errors in MacMillen and Landman's work are overstated.

Abstract

In a recent paper Hao et al. [Phys. Rev. B 80, 035329 (2009)] reported variational calculations of energy spectrum for shallow hydrogenic donor in the structure of semiconductor/insulator/metal with a new type of trial wave function. They also performed calculations for semiconductor/insulator system and found that their method gives energy values lower than those obtained by MacMillen and Landman [Phys. Rev. B 29, 4524 (1984)]. As follows from these results MacMillen and Landman have got much larger errors in energy values than they expected. However we confirm that the theoretical approach suggested by MacMillen and Landman gives rather accurate energy values for the system of hydrogenic donor near the interface between semiconductor and insulator.