Pre-fabrication gettering and bulk hydrogenation processes are applied to lowbulk-lifetime (25 μs) p-type Czochralski silicon wafers before silicon heterojunction (SHJ) solar cell fabrication, resulting in effective minority carrier lifetime enhancements by a factor of six. On complete SHJ solar cells, this translates to an improvement in the open-circuit voltage (V OC ) of 71 mV, resulting in V OC values as high as 692 mV. This remarkably high V OC suggests that efficiencies approaching 25% could be possible for low-cost p-type Czochralski silicon wafersnot the typical expensive, high-quality n-type ones with lifetimes of several millisecondsin the near future. This method is also likely applicable to n-type SHJ solar cells to reduce the incoming wafer lifetime requirements and to other silicon solar cell structures featuring passivated contacts.Hydrogenated amorphous silicon (a-Si:H) thin films provide excellent surface passivation of crystalline silicon wafers. [1] This has enabled open-circuit voltages (V OC ) of 750 mV in silicon heterojunction (SHJ) solar cells [2] and resulted in multiple worldrecord efficiencies of over 25%, [3,4] with a current record of more than 26.6% using an interdigitated back-contact structure. [4] One attributed strength of the SHJ technology is the ability to fabricate cells at temperatures below 250 C to reduce processing costs and avoid "poisoning" the silicon bulk during high-temperature processes. [5,6] However, the exclusive use of low processing temperatureswhich is required because of the loss of hydrogen from the a-Si: H films at higher temperatureseliminates the possibility of improving the quality of the silicon bulk throughout the cell fabrication sequence with gettering and hydrogenation. This is primarily due to the low diffusion coefficients of impurities including hydrogen and iron at such temperatures. [7,8] As a result, to take full advantage of the excellent surface passivation offered by SHJ structures, highquality n-type Czochralski (Cz), or float-zone silicon wafers with millisecond starting lifetimes are required to make high-efficiency solar cells. [7] This strict wafer-lifetime requirement increases the solar cell production cost and limits SHJ cells to premium markets.To broaden the application of SHJ structures and reduce the high materials cost of n-type silicon wafers, p-type Cz silicon wafers could be used. In fact, p-type Cz wafers can have bulk lifetimes of over 1 ms [9] and can be used to fabricate solar cells with V OC s of up to 730 mV. [10] However, the commercial-grade p-type Cz wafers used for mass production of aluminium back-surface field (Al-BSF) and passivated emitter and rear cell (PERC) structures often have much lower lifetimes (below 200 ms), which lead to substantially lower V OC and efficiency values than those of their n-type counterparts. Despite these poor lifetimes, cells fabricated from these wafers have demonstrated V OC s of approximately 686 mVand record efficiencies of 22.7% using the PERC cell technology.