Initialization of Nanowire or Cluster Growth Critically Controlled by the Effective V/III Ratio at the Early Nucleation Stage

Abstract

For self-catalyzed nanowires (NWs), reports on how the catalytic droplet initiates successful NW growth are still lacking, making it difficult to control the yield and often accompanying a high density of clusters. Here, we have performed a systematic study on this issue, which reveals that the effective V/III ratio at the initial growth stage is a critical factor that governs the NW growth yield. To initiate NW growth, the ratio should be high enough to allow the nucleation to extend to the entire contact area between the droplet and substrate, which can elevate the droplet off of the substrate, but it should not be too high in order to keep the droplet. This study also reveals that the cluster growth between NWs is also initiated from large droplets. This study provides a new angle from the growth condition to explain the cluster formation mechanism, which can guide high-yield NW growth.

High-Performance Multiwavelength GaNAs Single Nanowire Lasers

“…This indicates the existence of twin defects at the switching interfaces, which correspond to the positions of the dark lines observed in the TEM images. The lower density of structural defects in the SAE-grown NWs is likely caused by a higher V/III ratio during the growth, consistent with the previous studies. − …”

“… 21 , 22 In addition, in order to improve the structural uniformity of the NWs, we also increased the V/III ratio to 3. According to previous studies, 23 − 28 a high V/III ratio improves crystallographic properties of III–V NWs by suppressing formation of planar structural defects, such as rotational twins. It should also ensure a uniform nitrogen distribution during the vapor–solid growth of the GaNAs shell, similar to the case of thin film growth.…”

“…The lower density of structural defects in the SAE-grown NWs is likely caused by a higher V/III ratio during the growth, consistent with the previous studies. 23 − 28 …”