Two strategies for enhancing photovoltaic (PV) performance in chalcopyrite solar cells were investigated: Cu1-xKxIn1-yGaySe2 absorbers with low K content (K/(K+Cu), or x similar to 0.07) distributed throughout the bulk, and CuIn1-yGaySe2 absorbers with KIn1-yGaySe2 grown on their surfaces. Distributing K throughout the bulk absorbers improved power conversion efficiency, open-circuit voltage (V-OC) and fill factor (FF) for Ga/(Ga+In) of 0, 0.3 and 0.5. Surface KIn1-yGaySe2 and bulk x similar to 0.07 Cu1-xKxIn1-yGaySe2 films with Ga/(Ga+In), or y of 0.3 and 0.5 also had improved efficiency, V-OC, and FF, relative to CuIn1-yGaySe2 baselines. On the other hand, y similar to 1 absorbers did not benefit from K introduction. Similar to Cu1-xKxInSe2, the formation of Cu1-xKxGaSe2 alloys was favored at low temperatures and high Na supply by the substrate, relative to the formation of mixed-phase CuGaSe2 + KGaSe2. KIn1-yGaySe2 alloys were grown for the first time, as evidenced by X-ray diffraction and ultraviolet/visible spectroscopy. For all Ga/(Ga+In) compositions, the surface KIn1-yGaySe2 absorbers had superior PV performance in buffered and buffer-free devices. However, the bulk x similar to 0.07 absorbers only outperformed the baselines in buffered devices. The data demonstrate that KIn1-yGaySe2 passivates the surface of CuIn1-yGaySe2 to increase efficiency, V-OC, and FF, while bulk Cu1-xKxIn1-yGaySe2 absorbers with x similar to 0.07 enhance efficiency, V-OC, and FF by some other mechanism.