The discharge characteristics of a multielectrode dual coplanar in a mercury-free flat fluorescent lamp were investigated using brightness-efficiency measurement and the infrared (IR) spectrum and intensified charge coupled device (ICCD) characteristics. The level of brightness was above 14 900 cd/m² under the conditions of neon-–50% xenon–8% He gas composition, 150 Torr pressure, and 20 kHz alternating current pulse. The ICCD results revealed a faster and wider discharge with a Ne–50% Xe–8% He gas composition. The effect of adding helium (He) to Ne–50% Xe revealed a faster peak emission, as confirmed by ICCD images. From the gated IR emission spectrum, the intensity ratio of I_823 nm/I_828 nm was ∼ 8% higher with Ne–50% Xe–8% He than with Ne–50% Xe under the same pressure and applied voltage conditions.