Sevroal properties of glass-silicon heterojunctions have been studied as a function of glass composition. Oxide and chalcogenide glasses of both insulating and semiconducting behavior were investigated. The current-voltage characteristic indicates space-charge-limited currents in the glass film regardless of composition. An exponential trap distribution is suggested and trap density calculations agree with literature results. Capacitance-voltage measurements show that chalcogenide glass/silicon structures behave like ideal abrupt heterojunctions.