Combine 2 tablespoons lime juice, 1/2 tablespoon oil, 1/4 teaspoon salt, lemon pepper, and chicken in a large zip-top plastic bag. Seal and marinate in refrigerator 30 minutes.
While chicken marinates, heat 1/2 tablespoon oil in a cast-iron skillet over high heat. Add corn, onion, and bell peppers; saute 4 to 5 minutes or until slightly blackened. Transfer corn mixture to a bowl; stir in 1 tablespoon lime juice, 1/2 tablespoon oil, 1/4 teaspoon salt, cilantro, and black pepper.
Remove chicken from bag; discard marinade. Place chicken on grill rack coated with cooking spray; grill 4 to 5 minutes on each side or until done. Serve chicken with salsa and lime slices. Garnish with cilantro sprigs, if desired.