Barrier width and built-in electric field effects on hydrogenic impurity in wurtzite GaN/AlGaN quantum well

Based on the effective mass approximation, barrier width and built-in electric field effects on the donor binding energy of hydrogenic impurity in wurtzite (WZ) GaN/AlGaN quantum well (QW) are investigated by means of a variational method. Numerical results show that the strength of the built-in electric field inside the well layer increases and then remains constant with increasing the barrier width in WZ GaN/AlGaN QW. Moreover, for any impurity case, the donor binding energy is insensitive to the variation of the barrier width in the QW with large barrier width. In addition, it can also be found that when Al composition increases, the donor binding energy increases for impurities localized inside the right side of the QW; however, the donor binding energy decreases slightly for impurities located at the center and left side of the QW.

Graphical abstractFor any impurity case, the donor binding energy is insensitive to the variation of the barrier width in the wurtzite GaN/AlGaN quantum well.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The built-in electric field inside well layer remains constant when the barrier width is larger. ► The donor binding energy is insensitive to the large barrier width in the QW. ► The increase of Al content affects obviously the impurity states localized inside the right well.