Spin-polarized electrons can be efficiently extracted from an n-doped semiconductor layer (n-S) by forming a modified Schottky contact with a ferromagnetic material (FM) and a .delta.-doped layer at an interface under forward bias voltage conditions. Due to spin-selection property of the FM-S junction, spin-polarized carriers appear in the n-doped semiconductor layer near the FM-S interface. If a FM-n-n'-p heterostructure is formed, where the n' region is a narrower gap semiconductor, polarized electrons from the n-S region and holes from the p-S region can diffuse into the n'-S region under the influence of independent voltages applied between the FM and n' regions and the n' and p regions. The polarized electrons and holes recombine in the n'-S region and produce polarized light. The polarization can be controlled and modulated by controlling the applied voltages.