Spectrally-Narrowed Emissions from Organic Crystals Having a One-Dimensional Grating on Their Surface

Abstract

We have succeeded in directly engraving one-dimensional diffraction gratings on the surface of organic semiconducting oligomer crystals by using focused ion beam (FIB) lithography and laser ablation (LA) methods. The FIB method enabled us to shape the gratings with varying periods down to ~150 nm. With the LA method a large-area grating with a ~500-nm period was readily accessible. All the above crystals indicated spectrally-narrowed emission (SNE) lines even in the case of shallow groove depths ~2-4 nm. In particular, we definitively observed the SNE pertinent to the first-order diffraction with the crystal having the diffraction grating of a 148.3-nm average period. The present results indicate utility of the built-in gratings that can directly be fabricated on the surface of the crystals.

Optically and electrically excited emissions from organic semiconducting oligomer crystals

“…The organic semiconductor layer (either an amorphous thin film or a thin crystal) is deposited (or laminated) onto the diffraction grating. Alternatively the diffraction grating can directly be engraved on the organic semiconductor layer …”

Organic Single‐Crystalline Semiconductors for Light‐Emitting Applications: Recent Advances and Developments

“…Recently, Hotta and co-workers focused on the focused ion beam (FIB) technique for the fabrication of the DFB-cavity structure. [135] Laterally emitted light occurring from the weak excitation was demonstrated with angle-dependence.…”

“…By replacing a plastic substrate, flexible DFB lasers based on OSCSs can be achieved with highly mechanical robustness. Recently, Hotta and co‐workers focused on the focused ion beam (FIB) technique for the fabrication of the DFB‐cavity structure . Laterally emitted light occurring from the weak excitation was demonstrated with angle‐dependence.…”

Organic single-crystal light-emitting field-effect transistors

“…2 provides a unique opportunity to design a suitable resonator and incorporate it into a device. Angle-resolved light emissions from a slab organic crystal supply us further useful information about the resonator optimization [11]. Recent progress will be presented on the day.…”