This is a repository copy of Chiral topological photonics with an embedded quantum emitter.

Article:Mehrabad, M.J., Foster, A.P. orcid.org/0000-0002-5817-0008, Dost, R. orcid.org/0000-0002-8578-0389 et al. (6 more authors)

No abstract

The integration of quantum emitters within topological nanophotonic devices enables the control of light–matter interactions at the single photon level. Here, we experimentally realize an integrated topological add–drop filter and observe multiport chiral emission from single photon emitters (quantum dots) embedded within the device. The filter is imprinted within a valley-Hall photonic crystal membrane and comprises a resonator evanescently coupled to a pair of access waveguides. We show that the longitudinal modes of the resonator enable the filter to perform wavelength-selective routing of light, protected by the underlying topology. Furthermore, we demonstrate that for a quantum dot located at a chiral point in the resonator, selective coupling occurs between well-defined spin states and specific pairs of the filter output ports. The combination of multiport routing, allied with the inherent nonreciprocity of the device at the single photon level, presents opportunities for the formation of complex quantum optical devices, such as an on-chip quantum optical circulator.

In this study, high efficient heterojunction crystalline silicon solar cells without using an intrinsic layer were systematically investigated. The effect of various parameters such as work function of transparent conductive oxide (ϕTCO), density of interface defects, emitter and crystalline silicon thickness on heterojunction silicon solar cell performance was studied. In addition, the effect of band bending and internal electric field on solar cell performance together with the dependency of cell performance on work function and reflectance of the back contact were investigated in full details. The optimum values of the solar cell properties for the highest efficiency are presented based on the results of the current study. The results represent a complete set of optimum values for a heterojunction solar cell with high efficiency up to the 24.1 % with VOC  0.87 V and JSC  32.69 mAcm -2 .