Organic quantum wells with multiple negative differential resistance peaks and its photoswitch effect

• An ordered smooth organic crystalline heteroepitaxy multilayer film was formed.
• A type II organic quantum well based on the multilayer film was constructed.
• Both electron and hole quantum well show symmetrical and multiple NDR peaks.
• The blueshifts of C4-IDQA and PTCBI absorption spectra were observed.
• A photoswitch device based on the organic quantum well was prepared.

Organic optoelectronic devices have experienced great progress in recent decades. However, quantum well has long been a challenge for organic semiconductors due to the weak intermolecular interactions, the difficulty of realizing high quality alternate crystalline films. Here, we construct a type II organic crystalline quantum well, in which both electron quantum well and hole quantum well show symmetrical and multiple negative differential resistance peaks, respectively. The blueshifts of absorption spectra and the peak voltage decreasing under illumination conditions are observed. Due to high absorption coefficient of organic semiconductors, photoswitch effect by taking advantage of negative differential resistance of organic quantum well, which owns very thin device structure is demonstrated. Our results prove the promising applications of organic quantum wells, which broaden the types of organic optoelectronic devices.

A meaningful type II organic quantum well based on high quality crystalline heteroepitaxy multilayer film is constructed. The symmetrical and multiple NDR peaks and the blueshifts of absorption spectra provide the solid and direct evidences of the realization of organic quantum wells. The photoswitch effect of the organic quantum well as an initial exploration on the optoelectronic application is also studied.Figure optionsDownload as PowerPoint slide