Inorganic-Organic Hybrid Technology for Light Emitting Diodes

Abstract: Since the first report of inorganic light emtting diodes a century ago the field of inorganic light emitting diodes has evolved rapidly. T he development of light emitting diodes technology has caused their efficiency and light output to increase exponentially, with a doubling occuring about every 36 months  since the 1960s, in a similar way to Moor´s law. the advances are generally attributed to the parallel development of the semiconductor technologies and advances in optics and material science. This trend is normally called Haitz´s law after Dr. Roland Haitz.on the other hand, during the last 30 years a new research and technology field of organic electronic materials has grown. Organic light emitting diodes is rapidly maturing for the development of large area light -emitting displays. The reasons behind that is the possibility of using uconventional substrates such as flexible plastic and glass and the availability of several very cheap production methods.This thesis deals with the demonstration and investigation of heterjuction light emitting diodes (LEDs) based on n-ZnO-nanorod/p-polymer hybrid layered structures. The devices were fabricated using low cost and flexible substrates (glass and plastic substrates). Both ZnO-nanorods and the polymer materials were grown using low temperature methods. Different configurations were used starting with single polymer emissive layer ending up with separate emissive and blocking layers. In addition, blend multilayer structures were also used. In each case the advantages and disadvantages were investigated. analyzed and discussed. In general room temperature photoluminescence and electroluminescence spectra of the LEDs provided a broad emission band covering a wide color range (430nm- 700nm), in which zinc vacancies, oxygen vacancies and polymer emission peaks are contributting to the observed broad emission.