Need to step up voltage from 1.2V to 5V in seebeck pelteir plate setup

My project is that I want to USB fire charger. Its a device that you place on or near fire that will use the Seebeck effect of a pelteir plate to charge a USB device.

So far I learned that i will only get 1.2 volts from a pelteir connected with a Schottky diode. USB ports need 5 V to charge any device.

I looked online on ways to step up voltage and the thing i found is a charge pump. Is the only way to step up voltages from 1.2 V to 5 V. I also found this link that steps up a solar panel voltage to 5 V, could the panel be swapped with a pelteir plate. (http://www.talkingelectronics.com/pr...ly5vSolar.html)

Thank you for your replies in advance.

For low current applications such as your charger a charge pump can be used. Alternatively a DC-DC converter using magnetics can be used.

However, the Peltier device 1.2 volt output is rather limiting. Few off-the-shelf charge pumps or DC-DC converters will operate at this low voltage. To get around this two or more Peltier devices can be connected in series. If this is not a problem five series connected devices will negate the need for a DC-DC converter.