A solar cell, comprising: a semiconductor substrate having a first conductivity type; an emitter layer at or adjacent to a surface of the semiconductor substrate, the emitter layer having a second conductivity type different from the first conductivity type; a back surface field layer at or adjacent to another surface of the semiconductor substrate, the back surface field layer having the first conductivity type; and electrodes (24, 34) comprising a first electrode electrically connected to the emitter layer, and a second electrode electrically connected to the back surface field layer; wherein the emitter layer comprises a high-concentration doping portion adjacent to the first electrode, and a low-concentration doping portion in a region that does not include the high-concentration doping portion, the low-concentration doping portion having a higher resistance than the high-concentration doping portion; wherein the high-concentration doping portion comprises a first region having a first resistance, and a second region having a second resistance higher than the first resistance, wherein the second region is positioned outside of the first region; wherein the second region includes second regions that are arranged at opposite sides of the first region; wherein the first resistance of the first region is 30 to 70 Ω/square (ohms/square), and the second resistance of the second region is 80 to 90 Ω/square; wherein the resistance of the low-concentration doping portion is 100 to 120 Ω/square; wherein a ratio of a width of each of the second regions to a width of the first region is 0.5 to 1.5; wherein the back surface field layer comprises another high-concentration doping portion adjacent to the second electrode, and another low-concentration doping portion in a region that does not include the another high-concentration doping portion, the another low-concentration doping portion having a higher resistance than the another high-concentration doping portion; wherein the another high-concentration doping portion comprises another first region having a first resistance, and another second region having a second resistance higher than the first resistance; and wherein the another second region includes second regions that are positioned at opposite sides of the another first region. a semiconductor substrate having a first conductivity type; an emitter layer at or adjacent to a surface of the semiconductor substrate, the emitter layer having a second conductivity type different from the first conductivity type; a back surface field layer at or adjacent to another surface of the semiconductor substrate, the back surface field layer having the first conductivity type; and electrodes (24, 34) comprising a first electrode electrically connected to the emitter layer, and a second electrode electrically connected to the back surface field layer; wherein the emitter layer comprises a high-concentration doping portion adjacent to the first electrode, and a low-concentration doping portion in a region that does not include the high-concentration doping portion, the low-concentration doping portion having a higher resistance than the high-concentration doping portion; wherein the high-concentration doping portion comprises a first region having a first resistance, and a second region having a second resistance higher than the first resistance, wherein the second region is positioned outside of the first region; wherein the second region includes second regions that are arranged at opposite sides of the first region; wherein the first resistance of the first region is 30 to 70 Ω/square (ohms/square), and the second resistance of the second region is 80 to 90 Ω/square; wherein the resistance of the low-concentration doping portion is 100 to 120 Ω/square; wherein a ratio of a width of each of the second regions to a width of the first region is 0.5 to 1.5; wherein the back surface field layer comprises another high-concentration doping portion adjacent to the second electrode, and another low-concentration doping portion in a region that does not include the another high-concentration doping portion, the another low-concentration doping portion having a higher resistance than the another high-concentration doping portion; wherein the another high-concentration doping portion comprises another first region having a first resistance, and another second region having a second resistance higher than the first resistance; and wherein the another second region includes second regions that are positioned at opposite sides of the another first region.