Fig. 7. (a) Continuous wave (CW) photoluminescence spectra, excitation at 500 nm; (b) time resolved photoluminescence decay at 760 nm for the pristine perovskite film and the bilayer series. Excitation at λexc = 460 nm, excitation density of 1 nJ cm–2. All the samples have been encapsulated to prevent degradation or any oxygen/moisture induced effects. Solid lines represent the fitting curve resulting from exponential fitting in the form of y = A1 × exp(–x/t1) + A2 × exp(–x/t2). See Table S2† for the fitting parameters.
