Air-stable, ambipolar heterojunction-based organic light-emitting field-effect transistors (OLEFETs) with a top-contact, multidigitated, long-channel geometry were produced, and the current-voltage-light emission (I-V-L) characteristics were systematically examined. Two active layers of p-type pentacene and n-type N,N'-ditridecylperylene-3,4,9,10-tetra carboxylic diimide (P13) as well as a protecting layer of 2,S-bis(4-biphenyl) thiophene (BP1T) were successively deposited using the neutral cluster beam deposition method. On the basis of the growth of high-quality, well-packed crystalline thin films, the OLEFETs demonstrated good field-effect characteristics, well-balanced ambipolarity, operational stability, and electroluminescence (EL) under ambient conditions. The operating conduction and EL mechanisms responsible for the observed recombination zone are discussed with the aid of light-emission images obtained using a charge-coupled device.