Hole density is __________ compared to electron density in a p type semiconductor.
Answers
Answer:
Explanation:
Assume that we have two n-type and p-type semiconductors (in solar cell) with equal light absorption, resulting in equal photogenerated electrons within them. Each excited electron results in a hole, so we should have equal amount of photogenerated holes in both of them, as well. Since the minority carriers are electrons and holes in p-type and n-type semiconductors, respectively, the order of increase in electron density in p-type semiconductor and hole density in n-type one are more sensible than increase in hole density in p-type semiconductor and electron density in n-type one, respectively. The mobility of electron is more than hole, so electrons as charge carriers can be more effective in solar cells.
Assume that we have two n-type and p-type semiconductors (in solar cell) with equal light absorption, resulting in equal photogenerated electrons within them. Each excited electron results in a hole, so we should have equal amount of photogenerated holes in both of them, as well. Since the minority carriers are electrons and holes in p-type and n-type semiconductors, respectively, the order of increase in electron density in p-type semiconductor and hole density in n-type one are more sensible than increase in hole density in p-type semiconductor and electron density in n-type one, respectively. The mobility of electron is more than hole, so electrons as charge carriers can be more effective in solar cells.My question is this: Although the amount of photogenerated electrons is equal in p-type and n-type semiconductors, we consider p-type semiconductor as the absorption layer. Why?
Assume that we have two n-type and p-type semiconductors (in solar cell) with equal light absorption, resulting in equal photogenerated electrons within them. Each excited electron results in a hole, so we should have equal amount of photogenerated holes in both of them, as well. Since the minority carriers are electrons and holes in p-type and n-type semiconductors, respectively, the order of increase in electron density in p-type semiconductor and hole density in n-type one are more sensible than increase in hole density in p-type semiconductor and electron density in n-type one, respectively. The mobility of electron is more than hole, so electrons as charge carriers can be more effective in solar cells.My question is this: Although the amount of photogenerated electrons is equal in p-type and n-type semiconductors, we consider p-type semiconductor as the absorption layer. Why?Does the number of electrons differ in the n-type and p-type semiconductors? Does the photogenerated electron of p-type semiconductor has more freedom of action than that of photogenerated electron in n-type one?