Sub-single exciton optical gain threshold in colloidal semiconductor quantum wells with gradient alloy shelling
NATURE COMMUNICATIONS, cilt.11, sa.1, 2020 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 11 Sayı: 1
- Basım Tarihi: 2020
- Doi Numarası: 10.1038/s41467-020-17032-8
- Dergi Adı: NATURE COMMUNICATIONS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Agricultural & Environmental Science Database, BIOSIS, CAB Abstracts, Chemical Abstracts Core, EMBASE, Geobase, INSPEC, MEDLINE, Veterinary Science Database, Directory of Open Access Journals
- Ankara Üniversitesi Adresli: Hayır
Özet
Colloidal semiconductor quantum wells have emerged as a promising material platform for use in solution-processable lasers. However, applications relying on their optical gain suffer from nonradiative Auger decay due to multi-excitonic nature of light amplification in II-VI semiconductor nanocrystals. Here, we show sub-single exciton level of optical gain threshold in specially engineered CdSe/CdS@CdZnS core/crown@gradient-alloyed shell quantum wells. This sub-single exciton ensemble-averaged gain threshold of (N-g)approximate to 0.84 (per particle) resulting from impeded Auger recombination, along with a large absorption cross-section of quantum wells, enables us to observe the amplified spontaneous emission starting at an ultralow pump fluence of similar to 800 nJ cm(-2), at least three-folds better than previously reported values among all colloidal nanocrystals. Finally, using these gradient shelled quantum wells, we demonstrate a vertical cavity surface-emitting laser operating at a low lasing threshold of 7.5 mu J cm(-2). These results represent a significant step towards the realization of solution-processable electrically-driven colloidal lasers.