ITO/PTPD/Alq3/Mg:Ag heterostructure electroluminescent diodes have been fabricated using a novel poly-TPD for hole transport material.Their regularity of electroluminescent properties with the variety of Alq3 ETL thickness has been investigated.The influence of electric field on carrier recombination area has been discussed.Based on the theory of energy band and breakdown,it is considered to be a comprehensive result of redistribution of electric field on heterostructure device and the carrier transport and...