Monolithic Perovskite Silicon Tandem Solar Cells Fabricated Using Industrial p Type Polycrystalline Silicon on Oxide Passivated Emitter and Rear Cell Silicon Bottom Cell Technology

Combining a perovskite top cell with a conventional passivated emitter and rear cell PERC silicon bottom cell in a monolithically integrated tandem device is an economically attractive solution to boost the power conversion efficiency PCE of silicon single junction technology. Proof of concept perovskite silicon tandem solar cells using high temperature stable bottom cells featuring a polycrystalline silicon on oxide POLO front junction and a PERC type passivated rear side with local aluminum p contacts are reported. For this PERC POLO cell, a process flow that is compatible with industrial, mainstream PERC technology is implemented. Top and bottom cells are connected via a tin doped indium oxide recombination layer. The recombination layer formation on the POLO front junction of the bottom cell is optimized by postdeposition annealing and mitigation of sputter damage. The perovskite top cell is monolithically integrated in a p amp; 8722;i amp; 8722;n junction device architecture. Proof of concept tandem cells demonstrate a PCE of up to 21.3 . Based on the experimental findings and supporting optical simulations, major performance enhancements by process and layer optimization are identified and a PCE potential of 29.5 for these perovskite silicon tandem solar cells with PERC like bottom cell technology is estimate

Social Assistance in Developing Countries Database Version 5.0

The Social Assistance in Developing Countries Database is a user-friendly tool that provides summary information on social assistance interventions in developing countries. It provides a summary of the evidence available on the effectiveness of social assistance interventions in developing countries. It focuses on programmes seeking to combine the reduction and mitigation of poverty, with strengthening and facilitating household investments capable of preventing poverty and securing development in the longer term. The inclusion of programmes is on the basis of the availability of information on design features, evaluation, size, scope, or significance. Version 5 of the database updates information on existing programmes and incorporates information on pilot social assistance programmes in Latin America, Asia and Africa. It also adopts a new typology that distinguishes between social assistance programmes providing pure income transfers; programmes that provide transfers plus interventions aimed at human, financial, or physical asset accumulation; and integrated poverty reduction programmes. This new typology has, in our view, several advantages. It is a more flexible, and more accurate, template with which to identify key programme features. It provides a good entry point into the conceptual underpinnings of social assistance programmes