low-cost manufacturing methods have been studied for two types of thin-film solar cells on glass substrates. one is a heterojunction cds/cuinse sub 2 deposited by chemical spray pyrolysis; the other is a cds/cdte cell that is prepared by silk screening and sintering. in the spray pyrolysis program, we have succeeded in deposition cds layers that, after a brief heat treatment in n-cd atmosphere, have a resistivity of less than 0.1 omega -cm. we have also spray-deposited cuinse sub 2 films that after a brief heat-treatment exhibit the desired chalcopyrite structure. heterojunctions with photovoltaic response were produced by spray pyrolysis. the fill factors were low; consequently, the efficiency was less than 1. the conditions for heat-treatment of the two layers of the heterojunction are mutually incompatible, and the resistance of the cds layer increases during the cuinse sub 2 deposition. also, the condition for the conversion of the sphalerite to chalcopyrite seems to destroy the junction. a chemical thermodynamic study of the spray pyrolysis process has been useful in understanding and directing the spray pyrolysis program the sintered cells are prepared by first applying a cds layer containing a cdcl sub 2 flux and gacl sub 2 dopant to a borosilicate glass substrate. the layer is sintered in a n-cd atmosphere, then a cdte layer (also containing cdcl sub 2 flux) is applied and sintered in nitrogen. the cdte is converted to p-type by immersion in a cucl solution. metallic paint electrodes are then applied. we have obtained photovoltaic response with v/sub oc/ ranging up