Thermodynamic Determination of Work Functions of Bound Multiexciton Complexes

We present direct thermodynamic measurements of the work functions (φ) of bound multiexciton complexes in Al-, B-, and P-doped Si. We find that the value of φ differs in a number of cases from those obtained by assuming ground-state to ground-state transitions for some of the lines seen in luminescence. All the measured values of φ are found to be less than the work function for the electron-hole liquid.