Acne is caused by blocked pores becoming aggravated by bacteria found naturally on the surface of the skin. In warmer climates where sunlight is stronger, the light can kill off the acne bacteria and improve your complexion.
UV light was used to treat acne but this practice has reduced due the worries over skin cancer. It would, therefore, not be advisable to use sunbeds as a method to treat acne.
Some acne preparations, like Differin and Epiduo, make your skin more sensitive to light. During treatment, exposure to strong sunlight should be avoided to prevent burning and skin damage.