Efficient and Directed Nano-LED Emission by a Complete Elimination of Transverse-Electric Guided Modes

Abstract

A key to the success of solid-state lighting is an ultraefficient light extraction, ∼90%. Recent advances in nanotechnology, particularly in creating nanorods, present an unprecedented opportunity to manipulate optical modes at nanometer scales. Here, we report an optically pumped nanorod light-emitting diode (LED) with an ultrahigh extraction efficiency of 79% at λ = 460 nm without the use of either a back reflector or thin film technology. We demonstrated experimentally three key mechanisms for achieving high efficiency: guided mode-reduction, embedded quantum wells, and ultraefficient light out-coupling by the fundamental HE(11) mode. Furthermore, we show that size reduction at nanoscale represents a new degree-of-freedom for alternating and achieving a more directed LED emission.

Full-Color Single Nanowire Pixels for Projection Displays

“…15,25,27,[34][35][36] It is further envisioned that display technologies based on pixels of single nanowire LED arrays integrated on the same chip represent the ultimate light sources for the emerging three-dimensional (3D) projection display, flexible display, and virtual retinal display (VRD) technologies. [37][38][39][40] The radiation pattern and emission direction can be well controlled and tailored by the one-dimensional columnar structure of each single nanowire, [41][42][43] which is essential to achieving ultrahigh definition displays. In addition, pixels of single nanowire-based LED arrays can be much more efficient in heat dissipation and can operate at extremely large injection current levels.…”

Colloidal Moderate‐Refractive‐Index Cu2O Nanospheres as Visible‐Region Nanoantennas with Electromagnetic Resonance and Directional Light‐Scattering Properties

“…A main result induced by the interaction between the electric and magnetic dipole resonances is directional forward scattering, which is of fundamental importance for various device applications, such as solar cells, light‐emitting devices, and ultrasensitive sensors . Figure d shows as examples the far‐field scattering patterns of the nanospheres with different parameters as indicated by the four points in Figure a.…”

Computational electromagnetics for nanowire solar cells

“…Focusing on nanowire solar cells, while Kuo et al identified the HE11 mode of a single nanowire to be responsible for ultraefficient outcoupling of light from a single nanowire LED [55], Anttu identified the very same mode to be responsible for absorption enhancement in the nanowire solar cell [102].…”

“…Furthermore, there are structures that constitute hybrid approaches, such as a periodic square array with shorter randomly arranged wires in-between [51]. Compound semiconductor nanowires are also in the focus of research for light emitters [52][53][54][55], which have-as will be discussed in Sect. 4-contrary design goals to solar cells.…”