The phenomenon of carrier multiplication in quantum dots (QDs) is of great potential importance for the solar energy conversion. The study of multiple exciton generation can be carried out by monitoring the decay of biexcitons in the time-resolved photoluminescence of QDs [1]. We study spectral integrated time resolved photoluminescence (PL) of CdSe / ZnS QDs excited by a single laser pulse (pulse duration tp= 30 picoseconds and wavelength 532 nm) at room temperature. The luminescence of QDs and reference signal (Fig. 1a) were recorded simultaneously. Temporal reference signal was obtained by the propagation of a part of an exciting pulse through a Fabry-Perot resonator. In the reference channel the pulses duration are of 30 ps with a step of 67 ps (the basis of the FP resonator is 10 mm) shown in Fig.1b. The time resolution was 20 ps. We studied films obtained by the deposition of colloidal quantum dots on a glass substrate. The quantum dots size of 2.8 nm with the size dispersion (10%) was determined according to [2]. The photoluminescence decay (Fig.1c) consists of two components - fast (up to 100 ps) and slow. The slow decay component observed with our method of measurement was up to 4 ns. The fast decay component depended on the pump energy. The existence of the fast decay was determined by comparing the excitation pulse duration and the shape of its trailing edge with the same parameters of an initial part of the photoluminescence decay. Luminescence in Fig.1c demonstrates both of these differences. Long lived dynamics in PL is due to the generation of a single exciton per an excited QD. The appearance of the fast relaxation component in the time-resolved photoluminescence of QDs is attributed to the nonradiative Auger recombination of carriers when exciting more than one electronhole pair per a QD [1]. In our opinion, the recorded temporal features of the time-resolved photoluminescence of CdSe/ZnS QDs can correspond to the "biexciton dynamic signature” in conformity with [1].figureFig.1. Time-resolved photoluminescence of CdSe/ZnS quantum dots (time axis is the same for a,b,c): (a) Streak-camera “Agat-SF“screen shot with temporal reference and QD photoluminescence; (b) Fabry-Perot temporal reference (tp=30 ps, pulse step 67 ps); (c) QD time-resolved photoluminescence.