N-type silicon (Si) has been produced by doping with phosphorus (P). The charge-carrier population based on electrical conductivity measurments is determined to be 3.091*10^17 carriers/cm3 at room temperature.
1. Calculate the doping level of P (how much P has been added to the Si). Express your answer in units of g P / kg Si.
2. What is the majority charge carrier in the material described above?
A. p-type
B. n-type
C. electrons
D. holes
currect answer is 6.82e-3
how did u do this
To calculate the doping level of phosphorus (P) in n-type silicon (Si) and determine the majority charge carrier, we can follow these steps:
1. Calculate the doping level of P:
The doping level can be determined using the formula:
Doping Level (Np) = Carrier Concentration / Doping Efficiency
Given:
Carrier Concentration (n) = 3.091 * 10^17 carriers/cm³
Assuming a typical doping efficiency of 100%, which means each added P atom contributes one carrier.
To convert the carrier concentration to the number of P atoms per cm³, divide the carrier concentration by Avogadro's number (6.022 * 10^23 atoms/mol):
Doping Level (Np) = (3.091 * 10^17 carriers/cm³) / (6.022 * 10^23 atoms/mol)
Since we want to express the answer in units of g P / kg Si, we'll convert the number of P atoms to grams:
(1 mol P) / (6.022 * 10^23 atoms) = (Atomic mass of P) / (6.022 * 10^23 g)
The atomic mass of phosphorus (P) is approximately 30.9738 g/mol.
Now, we can calculate the doping level of P in units of g P / kg Si:
Doping Level (Np) = (3.091 * 10^17 carriers/cm³) / (6.022 * 10^23 atoms/mol) * (30.9738 g/mol) * (1000 g/kg)
2. Determine the majority charge carrier:
In n-type silicon doped with phosphorus (P), the majority charge carrier is the electron. Therefore, the correct answer is C. electrons.