In this work we report on the characterization of InAsNSb dilute nitride alloys and mutli-quantum well structures. InAsN epilayers with room-temperature photoluminescence emission have been successfully grown by MBE on InAs and GaAs substrates. By careful attention to growth conditions, device quality material can be obtained for N contents up to ~3% with band gap reduction which follows the band anti-crossing model. Mid-infrared light-emitting diodes containing ten period InAsNSb/InAs multi-quantum wells within the active region were fabricated. These devices exhibited electroluminescence up to room temperature consistent with e-hh1 and e-lh1 transitions within type I quantum wells in good agreement with calculations. Comparison of the temperature dependence of the EL with that of type II InAsSb/InAs reveals more intense emission at low temperature and an improved temperature quenching up to T~200 K where thermally activated carrier leakage becomes important and further increase in the QW band offsets is needed. This material system shows promise for use in mid-infrared diode lasers and other optoelectronic devices.