Method for reducing peak width of emission spectrum of organic solid-state semiconductor laser and organic electroluminescent device

A method for narrowing a full-width half-maximum (FWHM) of an emission wavelength peak of an emission spectrum of an organic electroluminescent device provided with:

• a hole injection section of injecting holes,
• an electron injection section of injecting electrons, and
• a light-emitting layer arranged between the hole injection section and the electron injection section to emit light by recombining holes and electrons, wherein
• the light generated in the light-emitting layer propagates in a lateral direction of the light-emitting layer, the method comprising:
• when a side of the light-emitting layer that is an exciton-dense region is on the electron injection section side, arranging a hole-blocking layer at a position between the light-emitting layer and the electron injection section and adjacent to the light-emitting layer;
• and
• when the side of the light-emitting layer that is the exciton-dense region is on the hole injection section side, arranging an electron-blocking layer at a position between the light-emitting layer and the hole injection section and adjacent to the light-emitting layer.

An organic solid-state semiconductor laser comprising:

• a hole injection section of injecting holes;
• an electron injection section of injecting electrons;
• a light-emitting layer arranged between the hole injection section and the electron injection section to emit light by recombining holes and electrons;
• and
• an optical resonator that propagates the emitted light inside the light-emitting layer,
• the organic solid-state semiconductor laser comprising
• a hole-blocking layer on the electron injection section side of the light-emitting layer so as to be adjacent to the light-emitting layer, or
• an electron-blocking layer on the hole injection section side of the light-emitting layer so as to be adjacent to the light-emitting layer.