Potassium and ion beam induced electron accumulation in InN

“We present angle resolved photoemission study of quantized electron accumulation subbands obtained from both clean and potassium deposited InN(0001¯) surfaces. Shifting of the quantized accumulation states toward higher binding energies upon low energy N2+ ion bombardment or a small amount of potassium adsorption is explained by the modification of the In-adlayer induced surface states. N2+ ion bombardment leads to a higher density of donor-type surface states by creating nitrogen vacancies near the surface. On the other hand, a small amount of K adsorbates initially donate their free electron to InN and result in more pronounced downward band bending. Eventually, further K adsorption leads to passivation of surface states and reduction of the surface electron accumulation. With the increase of the electron density, enhanced many-body interactions of electrons within the electron accumulation layer are observed.”