Extended Data Fig. 4: Temperature-dependent photoluminescence measurement.
From: Strain engineering and epitaxial stabilization of halide perovskites
a, b, Temperature-dependent photoluminescence of strained (a) and strain-free (b) α-FAPbI3 before normalization. c, d, Temperature-dependent photoluminescence of strained (c) and strain-free (d) α-FAPbI3 after normalization. Both samples exhibited uniform bandgap narrowing and FWHM narrowing with decreasing the temperature. e, f, Temperature-dependent photoluminescence (PL) FWHM of strained (e) α-FAPbI3 and strain-free (f) α-FAPbI3 with fitting. Results show that the strained α-FAPbI3 has a higher Γ0, γLO and ELO than that of strain-free α-FAPbI3 owing to the strain-induced crystalline quality reduction and the strain-enhanced carrier-phonon scattering. Γ0, temperature-independent emission linewidth term associated with the structural disorder scattering. γLO, charged-carrier-optical-phonon coupling constant. ELO, optical phonon energy.
