In recent years, Sn(IV)-based inorganic-organic metal halides and their doped compounds have attracted much attentions due to their excellent luminescence properties and good stabilities. However, their concrete performance in materials and devices still strongly depends upon the organic molecular structure and relevant mechanisms. Here, a series of Sb3+-doped 0D Sn(IV)-based halides (C20H20P)2SnCl6:x% Sb were synthesized by the antisolvent vapor diffusion technique, showing improved luminescence properties and wavelength-dependent emission character. (C20H20P)2SnCl6:20% Sb3+ exhibits an efficient warm white emission, which possesses dual bands at 481 and 637 nm with a photoluminescence quantum yield (PLQY) of 99.2%, at the 320 nm excitation. Moreover, it also gives efficient orange-red emission band at 637 nm with PLQY of 97.1% at the 365 nm excitation. In this 0D Sn(IV) compound, Sb doping tends to form [SbCl5]2-, whose high-energy emission band at 481 nm is from the self-trapped exciton (STE) out of the Sb singlet, and low energy orange-red emission band at 637 nm from the STE out of the Sb triplet. The latter is also accompanied with a DAP (donor-acceptor pair) transition between neighbouring SbCl5 and SnCl6 clusters. Their tunable and bright emission and excellent stability of (C20H20P)2SnCl6:20% Sb suit for a single-component WLED with warm white light emission as well as an information encryption system as shown.