Design of multilayered light emitting diode with charge-injecting polarization barriers

Summary form only given. Recently LED based on organic multilayered structures have attracted considerable interest since the use of charge transport layers (CTL) adjacent to light emitting layer (LEL) allows to improve their efficiency. Here we show that a proper choice of characteristics of CTL and LEL molecules, namely their relative polarizabilities(/spl alpha/), additionally to electron affinity and ionization potential, allows to create such type of polarization barriers at the interface of CTL and LEL, which (at /spl alpha/LEL /spl Gt//spl alpha/CTL) selectively injects one type of carriers into LEL, while confines the other one, increasing thus additionally the efficiency of LED. Contrary the opposite type of polarization barrier (realized at /spl alpha/LEL /spl Gt//spl alpha/CTL) will inhibit the charge-transfer from CTL to LEL, decreasing LED efficiency. We discuss the strategy for best choices of components of multilayered LEDs and present some preliminary experimental results on polarization barrier controlled LEDs.