The large electronic polarization in III-V nitrides allows for novel physics not possible in other semiconductor families. In this work, interband Zener tunneling in wide-band-gap GaN heterojunctions is demonstrated by using polarization-induced electric fields. The resulting tunnel diodes are more conductive under reverse bias, which has applications for zero-bias rectification and mm-wave imaging. Since interband tunneling is traditionally prohibitive in wide-band-gap semiconductors, these polarization-induced structures and their variants can enable a number of devices such as multijunction solar cells that can operate under elevated temperatures and high fields.

The role of spontaneous and piezoelectric polarization in III-V nitride heterostructure devices is discussed. Problems as well as opportunities in incorporating polarization in abrupt and graded heterojunctions composed of binary, ternary, and quaternary nitrides are outlined.

Discrimination targeting lesbian, gay, bisexual, and transgender (LGBT) students on college campuses occurs. Bystander intervention is important in supporting targeted students and improving campus climate for LGBT students. Peer-familiarity context (i.e., who the bystander knows in the situation) can play a role in bystander intervention, but researchers have not explored the nature of bystander intervention in specific peer-familiarity contexts concerning LGBT discrimination. Using hypothetical vignettes, we examine heterosexual students' (n ϭ 1616) intention to intervene across 4 peer-familiarity contexts, namely, when the bystander knows no one, only witnesses or targets, only perpetrator, or everyone. We explore the role of student inputs (sociodemographics, self-esteem, attitudes toward LGBT people and political ideology) and experiences (LGBT social contacts, LGBT and social justice course content, and perceived and experienced campus climate) on their intentions to intervene in these contexts. Multiple regression results suggest that across all peer-familiarity contexts, being older, having higher self-esteem, having LGBT friends, taking courses with social justice content, and affirming attitudes toward LGBT people were independently associated with higher intentions to intervene. Males were more likely than females to intervene when they knew no one, while females were more likely to intervene in all other contexts. Race/ethnicity, religious affiliation, witnessing heterosexist harassment, perceptions of campus climate for LGBT students, and student standing were significant in particular peer contexts. Recommendations to promote bystander intervention and future research are presented.

Indium gallium nitride nanowires show promise as being prime candidates for optical devices since they can be grown with band gaps spanning the visible spectra, while at the same time can be composed of stress free material. The goal of the work presented here was to obtain InGaN nanowires producing green emission at room temperature. Two growth recipes were found to yield InGaN nanowire growth on silicon substrates using plasma-assisted molecular beam epitaxy. At room temperature the photoluminescence (PL) of wire ensembles indeed peaked at 530 nm but, in addition, it was discovered that at low temperatures the emission often covered a broader (360–700 nm) spectrum. This broad optical range indicated indium content fluctuations in individual wires, wire-to-wire fluctuations, or a combination of the two. EDX measurements performed on single wires confirmed this hypothesis and correlated well with PL data. Low temperature PL studies of InGaN individual wires also revealed interwire and intrawire inhomogeneity of emission spectra stemming from a nonuniform indium distribution. The emission quantum yield for bright single wires was extracted to be more than 50% at 4 K. The findings suggest that the wire surfaces do not efficiently quench optical emission at low temperatures. These defect-free wires offer not only a potential path for green emitters, but also as integrated phosphors for broad spectral emission.

This article examines the public debate over marriage law to investigate how arguments based on claims about what is natural privilege some relationships while stigmatizing others and justifying discriminatory policies toward sexual minorities. Articles about same‐sex marriage appearing in major newspapers were content‐coded according to absence or presence of four dimensions of naturalness: change over time, norms, procreation, and welfare of children. Arguments invoking change over time were most frequent (39%), and procreation appeared least (10%). The use of arguments based on the moral status of marriage was associated with the use of each of the four dimensions based on naturalness. Mentions of race, including comparisons to racial struggles, appeared in 20% of the articles, making them just as common as child welfare. Results are discussed in terms of the power of the concept of naturalness to legitimize and maintain privilege, and the intersectionality of race and sexual orientation.