Luminescent solar concentrators (LSCs) are considered a promising technology to reduce the cost of electricity by decreasing the use of expensive photovoltaic materials, such as single-crystal silicon. In addition, LSCs are suitable for applications in building-integrated photovoltaics. Inorganic perovskite quantum dots (QDs) are promising candidates as absorbers/emitters in LSCs, due to their excellent optical properties including size/chemical-composition dependent absorption/emission spectrum, high absorption coefficient, high quantum yield and good stability. However, due to the large overlap between their absorption and emission spectra, it is still very challenging to fabricate large-area high-efficiency LSCs using perovskite QDs. Here we report the synthesis of mixed-halide perovskite CsPb(Br_xI_1−x)₃ QDs with small overlap of absorption and emission spectra, high quantum yield (over 60%) and absorption spectrum ranging from 300 to 650 nm. We use these QDs to build semi-transparent large-area LSCs that exhibit an external optical efficiency of 2% with a geometrical gain factor of 45 (9 cm in length). To date, these represent the brightest and most efficient solution-processed perovskite QDs based LSCs compared to LSCs based on perovskite thin films. The LSCs exhibit long term air stability without any noticeable variation in photoluminescence and lifetime under 4 W UV light illumination for over four hours.