THIN FILM TYPE ELECTROLUMINESCENCE ELEMENT

PURPOSE:To obtain an EL of low voltage drive capable of operation with an ordinary IC by including a P-type semiconductor or a thin layer containing a P-type semiconductor in a luminous layer. CONSTITUTION:A transparent electrode 22 is provided on a glass substrate. And an insulation layer 23, a luminous layer 24, a P-type semiconductor layer 25 and further a metal electrode via another insulation layer 23 are formed on the electrode 22 respectively in the order. By bonding the P-type semiconduc tor layer 25 to the luminous layer 24 as aforementioned, luminous threshold voltage substantially drops though a detailed mechanism is unknown. According estimation, this mechanism has a potential barrier at the interface of the P-type semiconductor layer 25 and the luminous layer 24 due to a difference in the work function thereof. When external voltage is applied, therefore, local and high voltage is applied to the interface, the pertinent number of electrons is injected from the P-type semiconductor layer 25 to the luminous layer 24 via the potential barrier due to a tunnel effect, and accelerated with a high electric field. Namely, it is estimated that an extremely substantial effect is caused due to the synergistic effect of the local high electric field application and the electron implantation.