Chiral Photodetector Based on GaAsN

Abstract

The detection of light helicity is key for various applications, from drug production to optical communications. However, the light helicity direct measurement is inherently impossible with conventional photodetectors based on III–V or IV–VI non‐chiral semiconductors. The prior polarization analysis by often moving optical elements is necessary before light is sent to the detector. A method is here presented to effectively give the conventional dilute nitride GaAs‐based semiconductor epilayer a chiral photoconductivity. The detection scheme relies on the giant spin‐dependent recombination of conduction electrons and the accompanying spin polarization of the engineered defects to control the conduction band. As the conduction electron spin polarization is, in turn, intimately linked to the excitation light polarization, the light polarization state and intensity can be determined by a simple conductivity measurement. This approach, removing the need for any optical elements in front of a non‐chiral detector, could offer easier integration and miniaturization. This new chiral photodetector could potentially operate in a spectral range from the visible to the infra‐red using (InGaAl)AsN alloys or ion‐implanted nitrogen‐free III–V compounds.

On-chip mid-infrared photothermoelectric detectors for full-Stokes detection

“…Up to date, one of the main approaches to detect SoP is based on the structural anisotropy or chirality from the natural materials. In general, photodetectors for linear polarization detection rely on the anisotropic absorption of one-dimensional nanowires or two-dimensional van der Waals materials 12 – 14 , while photodetectors for circular polarization detection are based on the chiral absorption of light in organic semiconductors and hybrid perovskites 15 , 16 , the spin photogalvanic effect in topological insulator or semimetals 17 – 20 , inverse spin Hall effect at metal-semiconductor interface 21 , 22 , and spin-dependent recombination of conduction electrons 23 , 24 . However, the applications of these polarization-sensitive photodetectors are hindered by intrinsic limitations, such as bandgap-dependent spectral responses, chemical instability, and low polarization sensitivity associated with small anisotropy or chirality.…”

Effect of growth temperature on nitrogen incorporation into GaAsN during liquid-phase epitaxy

“…Their unusual properties are due to the large electronegativity and the small atomic radius of nitrogen. Currently, their study is of considerable interest for applications in modern optoelectronics [1][2][3][4]. The substitution of a few percent of As atoms in GaAs by N atoms leads to substantial changes in the optical absorption because of a strong reduction in the bandgap energy [5].…”

A Systematic Study of Spin‐Dependent Recombination in GaAs1−xNx as a Function of Nitrogen Content

“…Indeed, the SDR in dilute nitrides is so large that its measurement via photoconductivity [8] has catalyzed device propositions ranging from spin filters [9] to spin-photon interfaces [10] and quantum sensors acting as light helicity detectors. [11] In parallel with efforts to develop device applications, significant fundamental progress in the identification of the SDR-active defect in these alloys has been made. In particular, the spin dynamics of the paramagnetic center were studied, [12] and optically detected magnetic resonance experiments have identified a Ga 2þ interstitial defect [9,13] as being responsible for SDR.…”

“…Indeed, the SDR in dilute nitrides is so large that its measurement via photoconductivity [ 8 ] has catalyzed device propositions ranging from spin filters [ 9 ] to spin–photon interfaces [ 10 ] and quantum sensors acting as light helicity detectors. [ 11 ]…”