Expert Recommendations in physical sciences

Statistical tools based on machine learning are becoming integrated into chemistry research workflows. We discuss the elements necessary to train reliable, repeatable and reproducible models, and recommend a set of guidelines for machine learning reports.

A key challenge in fabricating devices out of 2D materials is in making good electrical contact. This Expert Recommendation discusses the physics of electrical contacts and provides tips on improving contact quality.

This Expert Recommendation provides a guide to identifying practical situations where the likelihood ratio test statistic cannot be approximated by a χ² distribution and proposes adequate solutions.

Random lasing, which exploits disorder to enhance stimulated emission, challenges the conventional descriptions of lasing. This Expert Recommendation describes experimental methods required to properly assess and demonstrate random lasing action.

A group of experts suggests ways in which deep learning can be used to enhance the potential for discovery in multi-messenger astrophysics.

Legal inconsistencies and analytical limitations raise doubts about the possible enforcement of nanomaterial regulations.

This Perspective discussed the best practices for reporting lab-scale performance metrics in battery papers.

The performance of photodetectors fabricated from emerging semiconductors such as perovskites, quantum dots, two-dimensional materials or organics, for example, can be prone to misinterpretation. This Comment exposes the problems and proposes some guidelines for accurate characterization.

The solutions adopted by the high-energy physics community to foster reproducible research are examples of best practices that could be embraced more widely. This first experience suggests that reproducibility requires going beyond openness.

A proposed list of characterization items aims at improving reproducibility and consistency in experiments reporting the use of nanoengineered materials in biological applications.

Mobility is an important charge-transport parameter in organic, inorganic and hybrid semiconductors. We outline some of the common pitfalls of mobility extraction from field-effect transistor (FET) measurements and propose practical recommendations to avoid reporting erroneous mobilities in publications.

The definition and reporting of spatial resolution for coherent imaging methods varies widely in the imaging community. We advocate the use of a standard spoke-pattern imaging target and the mandatory inclusion of information about underlying a priori assumptions.

Mischaracterization of solar cell power conversion efficiencies and widespread publication of inconsistent data in scientific journals threatens to undermine progress in organic and hybrid photovoltaics research.

The quest for on-chip optical isolators has recently spawned many new isolator structures. However, there has been some confusion about the requirement of nonreciprocity. Here, we review the essential characteristics of an isolator.

The race to demonstrate new lasers, including electrically pumped polymer lasers, makes it a good time to reflect on the measurements that must be undertaken to support a claim of lasing.

A transistor that operates with photons rather than electrons is often heralded as the next step in information processing, but optical technology must first prove itself to be a viable solution in many different respects.

As the electronic performance of organic semiconductors and other emergent materials improves, researchers call for attention in extracting charge mobility values from field-effect transistors.