Fig. 4: Future directions of QD lasing.

a InAs/CdSe as an efficient near-infrared emitter with a straddling band alignment similar to CdSe/CdS. Taken from Franke et al.²⁶ b Quasi-2D CdSe/CdS nanoplatelets deposited on a photonic crystal wire enable thresholdless lasing under CW illumination. Taken from Yang et al.³¹ (right) Large modal gain coefficients of CdSe 3, 4, and 5 monolayer (ML) platelets from Guzelturk et al.⁴⁰ c Weakly confined perovskite QDs as highly tunable visible-light-emitting and optical gain material, taken from c Kovalenko et al.⁴¹ and d Geiregat et al.²²