When approaching the proton drip-line, beta-delayed particle spectroscopy becomes a very important tool for understanding the structure of atomic nuclei. In fact, so far from the beta-stability line, particle emission from highly excited states in the daughter nuclei becomes extremely competitive to deexcitation via gamma emission, since the Q-value gets large. Neutron-deficient silicon isotopes were investigated in an experiment performed at the MARS spectrometer at the Cyclotron Institute, Texas A&M University, with the aim of verifying the branching ratios for the known decay channels (beta-delayed one- and two-proton emission) and of identifying new ones, since the energy windows for beta-delayed proton+alpha and three-proton emission are open. The silicon ions were implanted into the Warsaw Optical Time Projection Chamber [1], where they decayed. The detector is particularly well suited for such studies, since it allows detection of these exotic decay modes with efficiency close to 100%. The preliminary results of the analysis of the beta decay of Si-23 will be presented. [1] M. Pomorski et al., Phys. Rev. C 83, 014306(R) (2011)