LiRE25 is a comprehensive evaluation of research at LiU. The core of the evaluation is the quality of research, but it also addresses research culture and the conditions for research. The purpose is to provide a basis for future quality work. The focus of LiRE25 is the evaluation units, which in most cases correspond to divisions at LiU’s twelve departments, and where Malmstens at Campus Lidingö also constituts an evaluation unit. 

LiRE25 is commissioned by the Vice-Chancellor. The design of the evaluation method and the planning and implementation of the evaluation have mainly been handled as a project in which the project group, the LiRE25 office, has done most of the work, but where several other parts of LiU’s organisation have also participated. 

The evaluation was carried out in two stages, a self-evaluation that each evaluation unit carried out in the autumn of 2024 followed by an external expert review in the spring of 2025. The external review was carried out by panels and resulted in recommendations aimed at both the evaluation units and other parts of LiU’s organisation. This final report is based on the self-evaluations and the panels’ re­ports. 

The self-evaluations have been the most important basis for the external review, but they have also had the dual purpose of providing the divisions with inspiration for how future quality work can be conducted. In addition, it has given LiU’s researchers the opportunity to express their views on how the university as a whole can be developed. As a side effect, the self-evaluations also contain many examples of successful quality work that other divisions can be inspired by. 

The panel reports contain recommendations that, for example, highlight the need for an expanded strategic thinking regarding future research directions, recruitments and scientific publication. Several of the panels have also identified the care of young researchers as an area that can be developed, as well as the mo­bility of LiU’s researchers. Increased international engagement is also highlighted as important by the panels. This applies to research collaborations as well as co-publication and to making better use of opportunities for EU funding. At the university level, the panels raise issues concerning LiU’s organisation and how the LiU strategy work can have a greater impact at the department and division level. 

This final report aims to provide an overview of the results of the evaluation. It can be read by all LiU employees, and particularly those who are in some way involved in research or research-supporting activities. The panels’ reports are also published on LiU’s website, and it will also be possible to interact with these texts via a chatbot. However, further work on using the results of LiRE25 at division level should primarily be based on the panels’ specific recommendations to each evaluation unit and the evaluation unit’s own self-evaluation. 

The Vice-Chancellor’s decision (Dnr LiU-2023-04517) to implement LiRE25 states: The research evaluation is an important part of the work on research quali­ty, but also in LiU’s strategy work. As part of Vision 2030 within the target area of Excellence and Benefit, the research evaluation is an important piece of the puzzle in how LiU can strategically develop its research going forward. It is a statement that signals that the results of LiRE25 will be used both for immediate efforts and for long-term strategic work. It is a strong hope that this report, together with oth­er documentation produced by the evaluation, will not only inspire quality work but also lead to an actual quality increase in the research at LiU! 

LiRE25 är en heltäckande utvärdering av forskning vid LiU. Utvärderingens kärna är forskningens kvalitet, men den tar också upp forskningskultur och forskningens förutsättningar. Syftet är att ge underlag för framtida kvalitetsarbete. I fokus för LiRE25 finns de utvärderade enheterna, som i de flesta fall överensstämmer med avdelningar vid LiU:s tolv institutioner och där också Malmstens vid Campus Lidingö utgjorde en utvärderad enhet.

LiRE25 är beställd av rektor. Utformningen av utvärderingsmetod samt planering och genomförande av utvärderingen har i huvudsak hanterats som ett projekt där projektgruppen, LiRE25-kansliet, gjort det mesta av arbetet men där också flera andra delar av LiU:s organisation medverkat.

Utvärderingen genomfördes i två steg, en självvärdering som varje utvärderad enhet genomförde under hösten 2024 följt av en extern expertgranskning under våren 2025. Expertgranskningen genomfördes av paneler och resulterade i rekommendationer riktade till såväl de utvärderade enheterna som till andra delar av LiU:s organisation. Denna slutrapport baseras på självvärderingarna samt panelernas rapporter.

Självvärderingarna har varit det viktigaste underlaget för expertgranskningen men de har också haft det dubbla syftet att ge avdelningarna inspiration till hur framtida kvalitetsarbete kan bedrivas. Dessutom, har det gett LiU:s forskare möjligheten att framföra synpunkter på hur universitetet i sin helhet kan utvecklas. Lite som en sidoeffekt finns i självvärderingarna också många exempel på framgångsrikt kvalitetsarbete som andra avdelningar kan inspireras av.

Panelrapporterna innehåller rekommendationer som till exempel lyfter behovet av ett utökat strategiskt tänk kring framtida forskningsinriktningar, rekry­teringar och vetenskaplig publicering. Flera av panelerna har också identifierat omhändertagandet av unga forskare som ett område som kan utvecklas liksom mobiliteten bland LiU:s forskare. Även ett utökat internationellt engagemang framhålls som viktigt av panelerna. Det gäller såväl forskningssamarbeten som sampublicering och att bättre utnyttja möjligheter till EU-finansiering. På det universitetsövergripande planet lyfter panelerna frågor kring LiU:s organisation samt hur det LiU-gemensamma strategiarbetet kan få större påverkan ut på av­delningsnivå.

Denna slutrapport syftar till att ge en översiktlig bild av utvärderingens resultat. Den kan med fördel läsas av alla LiU-medarbetare men särskilt de som på något sätt är inblandade i forskning eller forskningsstödjande verksamhet. Panelernas rapporter finns också publicerade på LiU:s webbplats och det kommer även att vara möjligt att interagera med dessa texter via en chattbot. Det fortsatta arbetet med att använda resultaten från LiRE25 på avdelningsnivå bör dock främst utgå från panelernas enhetsspecifika rekommendationer och den utvärderade enhetens egen självvärdering.

I rektors beslut (Dnr LiU-2023-04517) att genomföra LiRE25 står: Forskningsutvärderingen är en viktig del i arbetet med forskningskvalitet men också inom LiU:s strategiarbete. Som en del av Vision 2030 inom målområdet Excellens och nytta är forskningsutvärderingen en viktig pusselbit i hur LiU strategiskt kan utveckla sin forskning framåt. Det är en formulering som signalerar att resultatet av LiRE25 ska användas både för omedelbara insatser och för ett långsiktigt stra­tegiskt arbete. Det är en stark förhoppning från alla inblandade i LiRE25 att den­na rapport tillsammans med annat underlag som utvärderingen producerat inte bara inspirerar kvalitetsarbetet utan också leder till en faktisk kvalitetshöjning av forskningen vid LiU!

The construction of molecular photogears that can achieve through-space transmission of the unidirectional double-bond rotary motion of light-driven molecular motors onto a remote single-bond axis is a formidable challenge in the field of artificial molecular machines. Here, we present a proof-of-principle design of such photogears that is based on the possibility of using stereogenic substituents to control both the relative stabilities of two helical forms of the photogear and the double-bond photoisomerization reaction that connects them. The potential of the design was verified by quantum-chemical modeling through which photogearing was found to be a favorable process compared to free-standing single-bond rotation ("slippage"). Overall, our study unveils a surprisingly simple approach to realizing unidirectional photogearing. A stereochemical approach to transmitting the directional double-bond rotary motion of light-driven molecular motors through space onto a remote single-bond axis is put forth and successfully tested by means of quantum-chemical modeling. A key result in the assessment of the approach is that the desired photogearing process is favorable compared to the undesired, free-standing single-bond rotation process ("slippage") with which it competes.**image

Photochemical reactions enabling efficient transformation of aromatic systems into energetic but stable non-aromatic isomers have a long history in organic chemistry. One recently discovered reaction in this realm is that where derivatives of 1,2-azaborine, a compound isoelectronic with benzene in which two adjacent C atoms are replaced by B and N atoms, form the non-hexagon Dewar isomer. Here, we report quantum-chemical calculations that explain both why 1,2-azaborine is intrinsically more reactive toward Dewar formation than benzene, and how suitable substitutions at the B and N atoms are able to increase the corresponding quantum yield. We find that Dewar formation from 1,2-azaborine is favored by a pronounced driving force that benzene lacks, and that a large improvement in quantum yield arises when the reaction of substituted 1,2-azaborines proceeds without involvement of an intermediary ground-state species. Overall, we report new insights into making photochemical use of the Dewar isomers of aromatic compounds. Quantum-chemical calculations combined with molecular-dynamics simulations reveal mechanisms for improving the quantum yields by which aromatic compounds form their non-aromatic Dewar isomers, with potential implications in solar-energy storage.

We present a study of mobility field and temperature dependence for C60 with Kinetic Monte-Carlo simulations. We propose a new scheme to take into account polarization effects in organic materials through atomic induced dipoles on nearby molecules. This leads to an energy correction for the single site energies and to an external reorganization happening after each hopping. The inclusion of polarization allows us to obtain a good agreement with experiments for both mobility field and temperature dependence.

The influence of the interplay between symmetric and antisymmetric inter-molecular electron-phonon (e-ph) coupling mechanisms on the polaron stability and mobility in organic semiconductors has been theoretically investigated at a molecular level. A semi-empirical Holstein-Peierls model is used which in addition to the symmetric and antisymmetric inter-molecular e-ph interactions also includes an antisymmetric intra-molecular e-ph coupling. Our results show that the symmetric e-ph coupling plays the role of destabilizing the polaron as a result of temperature induced phonons that, via the symmetric coupling, affects the charge distribution of the polaron. Considering this kind of coupling, the parameter space for which the polaron is dynamically stable is strongly temperature-dependent. For the combination of symmetric e-ph coupling strength and temperature, which results in a stable polaron, the velocity of the polaron, and therefore also the charge carrier mobility, is not affected by the symmetric e-ph coupling strength.

We perform a theoretical study of the electronic properties of polyaromatic hydrocarbon (PAH) molecules, as well as benzene and graphene, adsorbed on copper and gold. The PAH molecules studied are coronene (C24H12), circumcoronene (C54H18) and circumcircumcoronene (C96H24), which we consider as gradual approximations to an infinite graphene layer. In order to understand how the size of the adsorbed PAH molecules influences the adsorbate-metal interactions, we generalize the approach used in our earlier study [Phys Rev B, 85 (2012), p. 205423] to decompose the binding energies and net charge transfers into separate contributions from specific groups of atoms, and we then show that the zigzag edges of the PAH molecules interact stronger with the metal surfaces than the armchair ones. We discuss the nature of binding in our model systems as well as the formation of interface dipoles. We show that for all model systems studied here, the charge rearrangement contribution to the interface dipoles can be expressed as the product of the charge involved in the formation of the dipole and the distance between well-defined centers of charge for electron accumulation and depletion. This distance is only marginally dependent on the specific PAH molecules, decreasing slowly with their size.

A semi-empirical Holstein-Peierls model is used to study the temperature effects on the polaron stability in organic semiconductors at a molecular scale. The approach takes into account both intra- and intermolecular electron-lattice interactions and is aimed at describing charge transport in the system. Particularly, we present a systematic numerical investigation to characterize the influence of both temperature and electric field on the stability as well as mobility of the polaron. It is found that the parameter space for which the polaron is dynamically stable is quite limited and the variations in some of these parameters strongly depend on the temperature. The electric field can play a role in further localizing the charge causing a compression of the lattice distortions associated with the polaron, increasing thereby its stability, up to a field strength of approximately 2.0 mV angstrom(-1). Considering field strengths higher than this critical value, the polaron is annihilated spreading charge through the lattice. Furthermore, we have studied the polaron mobility as a function of the anisotropy of the system, going from a one-dimensional system via a highly anisotropic two-dimensional system to a uniform two-dimensional system. There is a clearly observed mobility edge for the polaron; it exhibits a high mobility in the one-dimensional system but as the coupling in the second dimension is turned on the polaron slows down and becomes immobile in the uniform system. The results provided by this transport mechanism are in good agreement with experimental observations and may provide guidance to improve the charge transport in organic optoelectronic devices.

In this article, we analyze the electric field dependence of the hole mobility in disordered poly (p-phenylene vinylene). The charge carrier mobility is obtained from Monte Carlo simulations. Depending on the field strength three regions can be identified: the percolation region, the correlation region, and the inverted region. Each region is characterized by a different conduction mechanism and thus a different functional dependence of the mobility on the electric field. Earlier studies have highlighted that Poole-Frenkel law, which appears in the correlation region, is based on the type of correlation caused by randomly distributed electric dipoles. This behavior is thus observed in a limited range of field strengths, and by studying a broader range of electric fields, a more fundamental understanding of the transport mechanism is obtained. We identify the electric fields determining the transitions between the different conduction mechanisms in the material and we explain their physical origin. In principle, this allows us to characterize the mobility field dependence for any organic material. Additionally, we study the charge carrier trapping mechanisms due to diagonal and off-diagonal disorder, respectively. (C) 2015 AIP Publishing LLC.

The field-induced dynamics of polarons in armchair graphene nanoribbons (GNRs) is theoretically investigated in the framework of a two-dimensional tight-binding model with lattice relaxation. Our findings show that the semiconductor behavior, fundamental to polaron transport to take place, depends upon of a suitable balance between the GNR width and the electronphonon (eph) coupling strength. In a similar way, we found that the parameter space for which the polaron is dynamically stable is limited to an even narrower region of the GNR width and the eph coupling strength. Interestingly, the interplay between the external electric field and the eph coupling plays the role to define a phase transition from subsonic to supersonic velocities for polarons in GNRs.

We show that the spectral weights W mK ⃗ (k ⃗ ) used for the unfolding of two-component spinor eigenstates ∣ ∣ ψ SC mK ⃗ ⟩=|α⟩|ψ SC mK ⃗ ,α⟩+|β⟩|ψ SC mK ⃗ ,β⟩ can be decomposed as the sum of the partial spectral weights W μ mK ⃗ (k ⃗ ) calculated for each component μ=α,β independently, effortlessly turning a possibly complicated problem involving two coupled quantities into two independent problems of easy solution. Furthermore, we define the unfolding-density operator ρ ˆ K ⃗ (k ⃗ ;ɛ) , which unfolds the primitive cell expectation values φ pc (k ⃗ ;ɛ) of any arbitrary operator φ ˆ according to φ pc (k ⃗ ;ɛ)=Tr(ρ ˆ K ⃗ (k ⃗ ;ɛ)φ ˆ ) . As a proof of concept, we apply the method to obtain the unfolded band structures, as well as the expectation values of the Pauli spin matrices, for prototypical physical systems described by two-component spinor eigenfunctions.