[2] Tang C W, Vanslyke S A. Organic electroluminescent diodes [J]. Appl. Phys. Lett., 1987, 51:913-915

[3] Burroughes J H, Bradley D D C, Brown A R et al. Light-emitting diode Based on conjugated polymers [J]. Nature,1990, 347:539-541

[8] Tan H S, Chen L C, Wang X J et al. Color tunable Light-emitting diodes based on polymer/inorganic heterojunction [J]. Chin. Phys. Lett., 1998, 15(2): 137-139

[10] Wu C C, Chun J K W, Burrouws P E et al. PPV/Alqa heterostructure light emitting diodes [J]. Appl. Phys. Lett.,1995, 66(6): 653-655

[12] Tan H S, Yao J Q, Wang X et al. Novel alternating current electroluminescent devices with asymmetric structure based on polymer heterojunction [J]. Chin. Phys. Lett., 2002, 19(9)

[13] Parker I D. Carrier tunneling and device characteristic in polymer light-emitting diodes [J]. J. Appl. Phys., 1994,75(3): 1656-1666

[15] Wang Y Z, Gebler D D, Lin L B et al. Alternating-current light-emitting devices based on conjugated polymers [J]. Appl. Phys. Lett., 1996, 68(7): 894-896