“…On the contrary, the robustness of excitons in GaN and ZnO at RT has led to an increasing interest for these materials, especially after the first observation at RT of the strong coupling regime (SCR) 23 , and of polariton lasing in bulk- 24 and quantum well-based 25 GaN MCs elaborated on sapphire substrates. Concerning ZnO MCs, the SCR at RT has been reported more recently [26][27][28][29] , followed by polariton lasing at 120K 30 , then up to 250 K 31 , and finally at RT 32,33 . The difficulty to increase the number of pairs of the distributed Bragg reflectors (DBRs) due to the lattice and thermal expansion coefficient mismatch between silicon and nitrides prevented the achievement of polariton lasing in such samples 34,35 .…”