Patent ID: 7737458

Claim:
A light emitting device having a straight-line shape, comprising: a pair of first and second electrodes each having a straight-line shape which face each other; and a phosphor layer having a straight-line shape provided so as to be sandwiched between the pair of electrodes, wherein: at least one of the pair of first and second electrodes is a transparent electrode, the light emitting device having a straight-line shape further comprising at least one buffer layer provided so as to be sandwiched between the first or second electrode and the phosphor layer, the height of a potential barrier between the first electrode or second electrode and the phosphor layer via the buffer layer, the buffer layer being sandwiched between the first electrode or the second electrode and the phosphor layer, is lower than the height of a Schottky barrier between the first electrode or second electrode and the phosphor layer, which are directly connected without the buffer layer, a direct current voltage is applied between the first and second electrodes to emit light, one electrode of the first and second electrodes functions as an electron injecting electrode and the other electrode functions as a hole injecting electrode, and the buffer layer comprises at least one buffer layer of: a first buffer layer provided between the electron injecting electrode and the phosphor layer; and a second buffer layer provided between the hole injecting electrode and the phosphor layer.