Charge tunneling and cross recombination at organic heterojunction under electric fields S. Y. Yang, X. L. Zhang, Z. D. Lou and Y. B. Hou Eur. Phys. J. B, 59 2 (2007) 151-154 Published online: 17 October 2007 DOI: 10.1140/epjb/e2007-00282-4