Snaith group

Abstract:

The power conversion efficiency of tin-based halide perovskite solar cells is limited by large photovoltage losses arising from the significant energy-level offset between the perovskite and the conventional electron transport material, fullerene C₆₀. The fullerene derivative indene-C₆₀ bisadduct (ICBA) is a promising alternative to mitigate this drawback, owing to its superior energy level matching with most tin-based perovskites. However, the less finely controlled energy disorder of the ICBA films leads to the extension of its band tails that limits the photovoltage of the resultant devices and reduces the power conversion efficiency. Herein, we fabricate ICBA films with improved morphology and electrical properties by optimizing the choice of solvent and the annealing temperature. Energy disorder in the ICBA films is substantially reduced, as evidenced by the 22 meV smaller width of the electronic density of states. The resulting solar cells show open-circuit voltages of up to 1.01 V, one of the highest values reported so far for tin-based devices. Combined with surface passivation, this strategy enabled solar cells with efficiencies of up to 11.57%. Our work highlights the importance of controlling the properties of the electron transport material toward the development of efficient lead-free perovskite solar cells and demonstrates the potential of solvent engineering for efficient device processing.

Abstract:

This paper discusses sustainable renewable energy policies. The method used in this paper is a descriptive method that collects data from various sources literature studies and previous research. The results of the literature review show that the development of renewable energy in the European Union has three clusters dividing the share of renewable energy and the degree of dependency on energy imports based on the country. In Pakistan, the government has been designing a renewable energy policy since 2006 to supply sustainable energy to all consumers. In Nigeria, the electricity crisis and the need to reduce greenhouse gases spurred the development of renewable energy. Denmark has moved to wind power sources by increasing the share of renewable energy in the domestic electricity supply. The government encourages local ownership in the renewable energy sector, and many neighborhoods are connected to district heating systems that use renewable energy such as biomass. Increased investment in renewable energy technology will aid in addressing global energy concerns and hastening the transition to a low-carbon economy.Tulisan ini membahas tentang kebijakan energi terbarukan berkelanjutan. Metode yang digunakan dalam tulisan ini adalah metode deskriptif yang mengumpulkan data dari berbagai sumber dan studi literatur serta penelitian terdahulu. Hasil dari tinjauan literatur menunjukkan bahwa perkembangan energi terbarukan di Uni Eropa memiliki tiga kluster yang membagi negara-negara berdasarkan pangsa energi terbarukan dan tingkat ketergantungan impor energi. Di Pakistan, pemerintah telah merancang kebijakan energi terbarukan sejak tahun 2006 untuk memasok energi berkelanjutan kepada semua konsumen. Di Nigeria, krisis listrik dan kebutuhan untuk mengurangi gas rumah kaca memacu pengembangan energi terbarukan. Meskipun Nigeria memiliki potensi energi terbarukan yang besar, perkembangannya masih lambat. Diperlukan upaya lebih lanjut untuk meningkatkan pemanfaatan energi terbarukan melalui perjanjian kemitraan swasta, investasi dalam penelitian dan pengembangan, dan kebijakan berorientasi pasar.  Denmark telah melakukan peralihan ke sumber energi terbarukan dengan meningkatkan pangsa energi terbarukan dalam pasokan listrik domestik. Tenaga angin menjadi salah satu komponen utama energi terbarukan di Denmark. Pemerintah mendukung kepemilikan lokal dalam sektor energi terbarukan, dan sejumlah besar rumah tangga terhubung ke pemanas distrik yang menggunakan energi terbarukan seperti biomassa. Investasi yang lebih besar dalam teknologi energi terbarukan akan membantu mengatasi tantangan energi global dan mempercepat transisi ke ekonomi rendah karbon yang berkelanjutan

Abstract:

Metal halide perovskite based tandem solar cells are promising to achieve power conversion efficiency beyond the theoretical limit of their single-junction counterparts. However, overcoming the significant open-circuit voltage deficit present in wide-bandgap perovskite solar cells remains a major hurdle for realizing efficient and stable perovskite tandem cells. Here, a holistic approach to overcoming challenges in 1.8 eV perovskite solar cells is reported by engineering the perovskite crystallization pathway by means of chloride additives. In conjunction with employing a self-assembled monolayer as the hole-transport layer, an open-circuit voltage of 1.25 V and a power conversion efficiency of 17.0% are achieved. The key role of methylammonium chloride addition is elucidated in facilitating the growth of a chloride-rich intermediate phase that directs crystallization of the desired cubic perovskite phase and induces more effective halide homogenization. The as-formed 1.8 eV perovskite demonstrates suppressed halide segregation and improved optoelectronic properties.