I'm being a wise guy, but heavy rows and weighted chins are the two primary exercises for what you seek. In fact, here's a list of those that should be included in your workouts as you continue on your big back journey. I've taken into consideration that there are many readers of different training levels who will value exercise description. Starting from a fully extended hanging position, pull the body up to the chin, deliberately arching and contracting the lats throughout. Lower slowly, extend, and continue.
Form is everything, pure and controlled.
Lat contraction is your purpose, not going up and down roughly any way you can. Here we have lats totally engaged, outer and lower. Not everyone is remarkable in chinning. Give it your committed best and you may develop remarkable lats. Added attractions are bicep peak, grip strength, linear abs and minor pec action.