Simultaneous two-color lasing in a single CdSSe heterostructure nanosheet

Abstract

Abstract:The ability of a single monolithic semiconductor structure to emit or lase in a broad spectrum range is of great importance for many applications such as solid state lighting and multi-spectrum detection. But spectral range of a laser or light emitting diode made of a given semiconductor is typically limited by its emission or gain bandwidth. Due to lattice mismatch, it is typically difficult to grow thin film or bulk materials with very different bandgaps in a monolithic fashion. But nanomaterials such as nanowires, nanobelts, nanosheets provide a unique opportunity. Here we report our experimental results demonstrating simultaneous lasing in two visible colors at 526 nm and 624 nm from a single CdSSe heterostructure nanosheet at room temperature. The 97 nm wavelength separation of the two colors is significantly larger than the gain bandwidth of a typical single II-VI semiconductor material. Such lasing and light emission in a wide spectrum range from a single monolithic structure will have important applications mentioned above.

A monolithic white laser

“…MSHNs are otherwise grown as freestanding structures without epitaxial connection with the substrate, because the original growth substrates can be amorphous or non-lattice-matched crystals. The overall set-up and VLS growth mechanism are described in several earlier papers 24,33,48 and are shown schematically in Fig. 1a.…”

“…lumenera.com/). Due to the large size of the nanosheet structures, different longitudinal and transverse modes cause very close mode spacing 24 , so more modes are excited above the threshold with increasing pumping intensity. At a pumping level of 3.9 μJ, multimode lasing can be clearly observed.…”

“…In our efforts to achieve such an ultimate goal, we have already demonstrated two-colour lasing 24,25 from a single two-segment CdSSe nanosheet 24,26 and from a nanowire with a looped end 25 . We determined that two-colour lasing from a monolithic structure could best be achieved using a side-by-side cavity geometry (Supplementary Sections 1-4) rather than a longitudinal heterostructure, due to the absorption of short-wavelength emission by narrow-gap material.…”

Wavelength‐Tunable Micro/Nanolasers

“…Complete compositional variation in single nanostructures is a critical step in the process of attaining wide‐range wavelength tunability. These innovative chemical growth techniques have boosted the development of white‐light emission, multiwavelength MNLs, and wavelength‐tunable MNLs …”

Color‐Temperature Tuning and Control of Trichromatic White Light Emission from a Multisegment ZnCdSSe Heterostructure Nanosheet

“…Such procedures to remove LEDs from the original growth substrates and mounting to new common platform significantly increase the complexity and the cost of fabrication . This is why over the last several years significant efforts have been devoted to the growth of different materials on a given substrate utilizing the unique properties of nanoscale materials and growth techniques . It has been shown that wide coverage of the visible spectrum, from UV to IR, can be achieved with nanostructures grown on a single substrate using a single growth run .…”