Abstract: A transient absorption spectrometer using excitation by a pulse current, including: a central control unit; a pulse generator configured to generate a current pulse signal under an action of a first trigger signal sent by the central control unit, where the current pulse signal is applied to a sample to be tested such that the sample is in a non-luminous excited state for single-carrier injection or a luminous excited state for luminescence in which an electroluminescent signal is generated; a laser configured to emit a pulsed optical signal under an action of a second trigger signal sent by the central control unit; a beam splitter disposed in a light-exiting direction of the laser, and configured to split the pulsed optical signal into a detection optical signal and a reference optical signal, where the detection optical signal irradiates the sample to be tested to generate a detected optical signal; a data acquisition unit configured to acquire, under an action of a third trigger signal and a fourth trigge

Abstract: There is provided a quantum dot comprising a core comprising a semiconductor and a shell substantially covering the core. The core has a first side and a second side opposite the first side. The core is disposed eccentrically inside the shell such that the shell is thinnest at the first side and thickest at the second side. Moreover, the shell has a thickness of greater than or equal to zero at the first side. The core and the shell have different respective lattice constants such that the shell exerts a straining force on the core. The straining force is configured to modify an excitonic fine structure of the core.

Abstract: There is provided a quantum dot comprising a core comprising a semiconductor and a shell substantially covering the core. The core has a first side and a second side opposite the first side. The core is disposed eccentrically inside the shell such that the shell is thinnest at the first side and thickest at the second side. Moreover, the shell has a thickness of greater than or equal to zero at the first side. The core and the shell have different respective lattice constants such that the shell exerts a straining force on the core. The straining force is configured to modify an excitonic fine structure of the core.