If you are looking for bicep peak, you need to focus on the long head of the bicep. The hammer curl is perfect for this purpose :)

Standing in a split-stance position, hold a dumbbell in each hand  with your palms facing your body. Contract your abdominal muscles and pull your shoulder blades down and back. Your head and neck should be aligned with your spine. Do not allow the back to arch. Maintain these engagements throughout the exercise.
Exhale and slowly bend one elbow, the opposite arm should remain in the starting position. Keep the palms facing your body and your wrists straight without any bend. Do not allow the shoulders to shrug or the elbows to move forward..
Inhale and gently straighten the elbow and lower the dumbbell back to your starting position and repeat to the opposite side.