Check out this article from The Baltimore Sun on how to help your green pepper produce more fruit. A solution made of Epsom salts and warm water gives the pepper plant a boost of magnesium that is required at the flowering stage to produce more peppers.
Dissolve 1 teaspoon of Epsom salts in 4 cups of warm water then pour into a spray bottle. Spray the plant with this mixture, again 10 days later and in a few weeks.
I planted several of these this year, so excited to try this out!