Bright prospects for tin perovskite solar cells

A new study suggests why tin-based perovskites could be used to make solar cells that are not only really environmentally friendly but also very stable

Helmholtz-Zentrum Berlin für Materialien und Energie

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Various perovskite semiconductors for solar cells can be produced in glove boxes in the lab. Dr Artem Musiienko (right) heads the research group ‘Optoelectronic Materials and Photovoltaic Development’ at HZB.

view more 

Credit: Michael Setzpfandt / HZB

Perovskite solar cells are widely regarded as the next generation photovoltaic technology. However, they are not yet stable enough in the long term for widespread commercial use. One reason for this is migrating ions, which cause degradation of the semiconducting material over time. A team from HZB and the University of Potsdam has now investigated the ion density in four different, widely used perovskite compounds and discovered significant differences. Tin perovskite semiconductors produced with an alternative solvent had a particular low ion density — only one tenth that of lead perovskite semiconductors. This suggests that tin-based perovskites could be used to make solar cells that are not only really environmentally friendly but also very stable.

 

 

For over ten years, researchers worldwide have been investigating organometallic perovskite semiconductors for use in photovoltaics. Their research has focused mainly on perovskite solar cells that contain lead as the B cation in the ABX3 structure of the perovskite. Thanks to their efforts, the efficiency of lead-based perovskite solar cells has increased from 4% to over 27% today.  However, these materials still have some issues. It's not just the problematic heavy metal lead which is toxic; the semiconductor material also lacks long-term stability.

Tin-perovskites - a neglected topic

The lead in the structure can be replaced by tin, a non-toxic element. Although tin-based perovskite solar cells currently have a significantly lower efficiency than lead-based solar cells, this may be because research on the tin-perovskites is still in its infancy, says Dr Artem Musiienko, head of a research group at HZB and points out: ‘In purely theoretical terms, tin-based perovskite solar cells could even exceed the efficiency of lead-based perovskites.’

A new study provides a compelling argument for paying more attention to tin-based perovskites. One of the main reasons for the insufficient stability of perovskite solar cells to date is the presence of mobile halide ions in the material. As halide ions migrate, the material degrades, and the solar cell’s efficiency decreases over time.

Mobile ions in perovskites

Musiienko's team has now investigated this phenomenon together with the Antonio Abate group, HZB, and Felix Lang group, University of Potsdam. They examined four of the most relevant perovskite compositions and quantitatively measured the ion density and migration of ions in the material.

'We found not only that tin based perovskites have a lower concentration of mobile ions but also that they intrinsically exhibit a degradation time five times slower than that of lead based perovskites,’ says Musiienko. The tin perovskite materials were produced in the HZB's Hysprint laboratory. One of the tin perovskites was synthesized using a dimethyl sulfoxide (DSMO) solvent and the other using an alternative DMF-DMI  solvent. The solvent variation approach was used to demonstrate a route for avoiding tin oxidation due to strong DMSO coordination, as previously shown in several investigations [Chemistry of Materials (2022)].

Huge differences in ion density

In fact, they discovered that the lead-based perovskite exhibited the greatest ion density. This density was slightly lower in the lead-tin mixture and the tin perovskite. A big surprise was by the tin perovskite sample that had been produced using the alternative solvent: ‘This was really unexpected: these FASnI3 solar cells have ten times fewer mobile ions than the Pb-based solar cells. We also found that they exhibited excellent stability during operation for over 600 hours,’ says Shengnan Zuo, a PhD student in the team of Musiienko.

A compelling argument for tin-perovskites

‘We are convinced that tin-based perovskites have enormous potential and that investigating these materials is a very good idea. There are chances to significantly increase their efficiency and stability. This study paves the way for the development of innovative, stable thin-film solar cells with suppressed ion migration,’ says Musiienko.

---

Journal

ACS Energy Letters

DOI

10.1021/acsenergylett.5c02675 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Minimizing Ionic Losses in DMSO-Free Tin-Based Perovskite Solar Cells

 

FAU study finds connection between poor mental health and dark web use

Florida Atlantic University

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

People with suicidal thoughts were nearly three times more likely to use the dark web, while those engaging in self-injury or digital self-harm were up to five and 19 times more likely, respectively.

view more 

Credit: Florida Atlantic University

The dark web – a hidden corner of the internet accessed through privacy-preserving tools like the Tor browser – operates beyond the reach of traditional search engines and public platforms. Unlike the surface web, its architecture is deliberately designed to shield identities and activities from view, prioritizing anonymity over transparency.

Although the dark web has existed for more than 20 years, research assessing mental health differences between its users and those who stay on the surface web remains limited. Its pseudo-anonymous nature and emphasis on privacy may attract individuals with mental health vulnerabilities, potentially drawing them into these hidden spaces.

A small but growing body of research points to a possible connection between mental health challenges and dark web use. However, direct empirical comparisons between dark web users and surface web users – especially in the context of mental health – are scarce. While such links have been theorized, they have yet to be thoroughly investigated through systematic research, until now.

A new Florida Atlantic University study reveals significant mental health differences between dark web users and those who use only the surface web, and sheds light on a group whose involvement in this secretive online space has largely kept them outside the scope of traditional research.

Leveraging survey data collected from 2,000 adults in the United States, Ryan C. Meldrum, Ph.D., lead author and director of the School of Criminology and Criminal Justice within FAU’s College of Social Work and Criminal Justice, and collaborators, explored whether those who report dark web use differ from surface web users across five mental health indicators.

Published in the journal Cyberpsychology, Behavior, and Social Networking, the study finds that dark web users reported substantially higher levels of depressive symptoms and paranoid thoughts as compared to surface web users. In addition, there were substantial differences between dark web users and surface web users pertaining to suicidal thoughts, non-suicidal self-injury and digital self-harm.

Adults who reported suicidal thoughts had nearly three times greater odds of reporting dark web use. Likewise, those who reported non-suicidal self-injury (e.g. cutting or burning oneself) were nearly five times more likely to report use of the dark web, and individuals who had engaged in digital self-harm (anonymously posting hurtful or negative comments about themselves online) had more than 19 times greater odds of reported dark web use.

“Our findings suggest that many individuals who turn to the dark web may be doing so not just for privacy concerns, but as a reflection of deeper mental health struggles and the possible desire to socialize and engage in information-seeking in a context free of scrutiny that might otherwise be experienced on the surface web or offline,” said Meldrum. “This underscores the need for mental health professionals to recognize and understand the hidden digital spaces some individuals may be engaging with. The dark web isn’t just a technological frontier – it’s a human one, where vulnerability and pain often go unseen.”

The discovery that dark web users consistently report greater mental health vulnerabilities carries significant real-world implications. Equipping social workers and mental health practitioners to safely and ethically engage with individuals on the dark web could open new pathways to support those who may otherwise go unnoticed. Similarly, raising awareness among parents, educators and policymakers about the link between mental health and dark web use – just as has been done with problematic social media use – could be a valuable step forward.

“The dark web may seem like a world apart, but the psychological challenges many people bring into this space are very real,” said Meldrum. “We cannot afford to overlook these digital environments simply because they are used by a subset of internet users. If we are committed to reaching the most vulnerable, we must be willing to engage with them – even in the more hidden corners of the internet.”

Study co-authors are Raymond D. Partin, Ph.D., Department of Criminology and Criminal Justice, University of Alabama; Peter S. Lehmann, Ph.D., Department of Criminal Justice and Criminology, Sam Houston State University; and Salpi S. Kevorkian, Department of Criminology and Criminal Justice, Florida International University.

- FAU -

About Florida Atlantic University:

Florida Atlantic University serves more than 32,000 undergraduate and graduate students across six campuses along Florida’s Southeast coast. Recognized as one of only 21 institutions nationwide with dual designations from the Carnegie Classification - “R1: Very High Research Spending and Doctorate Production” and “Opportunity College and University” - FAU stands at the intersection of academic excellence and social mobility. Ranked among the Top 100 Public Universities by U.S. News & World Report, FAU is also nationally recognized as a Top 25 Best-In-Class College and cited by Washington Monthly as “one of the country’s most effective engines of upward mobility.” As a university of first choice for students across Florida and the nation, FAU welcomed its most academically competitive incoming class in university history in Fall 2025. To learn more, visit www.fau.edu.

---

Journal

Cyberpsychology Behavior and Social Networking

DOI

10.1177/21522715251397784 

Method of Research

Survey

Subject of Research

People

Article Title

Crying Out in the Dark? Exploring the Mental Health Vulnerabilities of Dark Web Users

 

Why do lower-class youths receive more online ads about making easy money?

A pioneering study by UPF finds that lower-class young people, especially boys, receive twice as many ads about risky financial products as their upper-class peers (15% vs. 8%), in addition to marked gender differences in online advertising

Universitat Pompeu Fabra - Barcelona

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

Young people with fewer financial resources, especially boys, are the most exposed to advertising about how to make easy money. So confirms a pioneering study by Pompeu Fabra University (UPF), which has for the first time analysed how the socioeconomic level and gender of young people influences the customized advertising they receive on TikTok and Instagram. Among other data, the study reveals that the percentage of lower-class youths who receive ads about risky financial products (15%) almost doubles that of their upper-class peers (8%).

The research is based on an online survey of 1,200 young people from all over Catalonia aged 14 to 30 that evaluated the contents of advertising videos that appear spontaneously on TikTok and Instagram. On these networks, young people from lower socioeconomic backgrounds receive the most ads related to risky financial services (such as quick loans, investing in cryptocurrencies...), betting, online gaming or content promising easy income and flexible jobs with few requirements. In contrast, the only type of advertising that frequently appears for upper-class young people is related to travel and leisure.

Carolina Sáez, study author: “when we look at ads that promise to improve on the social ladder, the differences are hugely accentuated”

The results of the study were recently published in an article in the journal Communication & Society. The main author of the article is Carolina Sáez, a researcher with the Communication, Advertising and Society (CAS) research group of the UPF Department of Communication, who has conducted the research under the supervision of CAS director Mònika Jiménez.  Also collaborating in the study is Isabel Rodríguez de Dios (University of Salamanca).

Researcher Carolina Saéz explains: “when we look at ads that promise to improve on the social ladder, the differences are hugely accentuated”. The study reveals that young people with fewer resources feel they are much more likely than upper-class people to receive ads that promise easy money through digital businesses (44% vs. 4%) or seemingly accessible jobs with no prerequisites (39% vs. 4%). They also state that they are far more likely to receive content encouraging them to make investments for immediate profits, for example through cryptocurrencies (33% vs. 4%). Other promises of quick progress, such as immediate job opportunities or earning money with the mobile phone, reveal equally large differences (27% vs. 3.5%); and the same applies for quick, non-requirement credit listings (21% vs. 3%).

Advertising on social media also reinforces gender stereotypes

The differences in the advertising received according to social class are far more marked among boys than among girls. For example, young, lower-class boys receive twice as many online gambling ads as upper-class boys (22% versus 11%).  Conversely, the percentage of girls who receive such ads shows a much smaller variation between lower class (6.7%) and upper class (5.6%) subjects.

The study found that gender differences in digital advertising are highly pronounced. Girls receive more than twice as many fashion (50% vs. 13%) and beauty ads than boys (71% vs. 28%), and more than three times the amount of advertising dealing with topics related to parenting (16% vs. 5%). However, boys view twice as many ads for sports (54% vs. 26%), online gaming (46% vs. 23%), technology and electronics (32% vs. 15%) and energy drinks (10% vs. 4%); and more than three times as many automotive (16% vs. 6%) or alcohol (10% vs. 4%) adverts.

Why can networks personalize the advertising they deliver to young people according to gender or social class?

Carolina Sáez explains: “While the European data protection framework limits access by digital platforms to personal data, the large volume of information that social networks accumulate from each user allows TikTok and Instagram algorithms to deduce young people’s sensitive data concerning their economic status, educational level, origin or employment status”.

The researcher has found evidence that confirms this deducive capacity of the algorithms. During the study, data from the postal address that the young people provided when filling out the questionnaire anonymously, was crossed with data from the Índex Socioeconòmic Territorial (IST - Small Area Socioeconomic Index) of the Government of Catalonia. The IST gives weighting to different factors (levels of employment, income, education, etc.) to determine the socioeconomic level of the country’s different neighbourhoods, towns and cities. So, “the socioeconomic status of each young person yielded by crossing their address with this official index, largely coincides with the conclusions of the algorithm”, Sáez explains.

Carolina Sáez: “Algorithmic advertising (...) takes advantage of the desire of young people from disadvantaged backgrounds to thrive socially”

The researcher warns: “Algorithmic advertising commercially exploits this information and takes advantage of the desire of young people from disadvantaged backgrounds to thrive socially”. Minors and young adults are among the most vulnerable to algorithmic advertising, because usually they are not sufficiently mature to deal with it. It should be remembered that on average, young Catalans get their first mobile phone at the age of 12.

Minors also receive advertising for alcohol or gambling

Sáez adds that another “unexpected” result of the research is that minors aged 14-17 have received ads for alcohol, gambling, e-cigarettes or energy drinks through social networks, despite European regulations protecting them from this type of advertising.

For all the above, the study concludes that there is a need to toughen the regulation and control of the use of AI in online advertising targeting young people, as well as their digital literacy to provide them with greater critical capacity as network users.

Reference article:

Sáez-Linero, C., & Jiménez-Morales, M. (2025). Young, lower-class, and algorithmically persuaded: exploring personalized advertising and its impact on social inequality. Communication & Society, 38(2), 63-80. https://doi.org/10.15581/003.38.2.005

---

Journal

Communication & Society

DOI

10.15581/003.38.2.005 

Method of Research

Survey

Subject of Research

People

Article Title

Young, lower-class, and algorithmically persuaded: exploring personalized advertising and its impact on social inequality