Fig. 4

TEM results of sample 1A and 1C, grown without and with supply of UDMH, respectively. The designation follows the panel names in Fig. 1. Electron energy loss (EEL) spectrum of sample 1A (a) and 1C (b), the incorporation of N in sample 1C is clearly revealed. TEM micrographs of sample 1A (c) and 1C (d). The inset in (c) is a Fourier filtered HRTEM image of a small SF-free region in sample 1A. Despite that the sample is a couple of degrees off the ⟨110⟩ zone axis, the ABCABC stacking of GaP is still visible, confirming the zincblende structure. SF-free sections in sample 1C are highlighted. Bright-field (e) and dark-field (f) TEM images show strong strain contrast along the line of the diagonal of SF-free region. Typical twist and splitting of Bragg line [63] in the large-angle convergent beam electron diffraction (LACBED) pattern in (g) confirms the presence of dislocation in the SF-free region (highlighted in dark cyan)