Solution-processed Cu2O and CuO are used as hole transport materials in perovskite solar cells. The cells show significantly enhanced open circuit voltage V oc, short-circuit current J sc, and power conversion efficiency (PCE) compared with PEDOT cells. A PCE of 13.35% and good stability are achieved for Cu2O cells, making Cu2O a promising material for further application in perovskite solar cells. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.